When the St. Louis Cardinals acquired third baseman Nolan Arenado from the Colorado Rockies just under one year ago, it filled a major hole in their 2021 roster–a hole that expanded further once it became evident throughout the 2021 season that Matt Carpenter had not merely taken a step back but was truly, truly washed. As overstated as Arenado’s Coors-fueled accomplishments in the Mile High city may have been by those claiming he was an inner-circle elite type of player, there was no dispute that he was a quite good player, and in his first season in St. Louis, Arenado delivered. While his 4.1 Wins Above Replacement represented his lowest full season total since 2014, a slight dip once a player crosses 30 years old is fairly predictable, and if a team is just going to give you a 4+ win player at a position of need, something the Colorado Rockies functionally did, you should probably be happy to just accept it.

As part of the agreement for Arenado to waive his no-trade clause to come to St. Louis, the third baseman added a second opt-out to his existing contract. The opt-outs were to come following the 2021 and 2022 season. The first was almost certainly not going to be exercised–despite whatever lessons you may have gleaned from 95% of Out of the Park Baseball 22 simulations, it would have taken a truly Herculean season for a player to forego the remaining six years and $179 million on a contract for their post-prime seasons with a lockout looming. Following 2022, with the labor situation hopefully a bit more solidified, Arenado opting out is at least plausible enough to consider–it would not be outlandish for a 31 year-old third baseman coming off of an excellent 2022 season to command more than five years and $144 million on the open market.

I think the most probable outcome is still that Arenado does not opt out–if he reaches his Steamer-projected 4.2 WAR for 2022, he might be able to beat 5/144, but probably not by much, and it’s a lot easier to gamble $144 million when it isn’t my money. But if he does opt out, what to do from a Cardinals perspective is relatively straightforward–they would submit the qualifying offer to him (assuming that this does not radically change–this off-season, it was a one-year, $18.4 million contract which, if declined, would net draft pick compensation from the team that signs him), Arenado would reject it under any circumstances which would have led to him opting out in the first place, and then Arenado would hit free agency. Whether the Cardinals would attempt to re-sign Arenado in earnest, however, might come down to the other third basemen in the Cardinals’ organization.

Nolan Arenado patrolled third base for the Cardinals for 92.6% of the team’s competitive innings in 2021. The only other player to start multiple games at third base, Matt Carpenter, is no longer a Cardinal, which is also the case for cameo third basemen Max Moroff and José Rondón. And while the one other player to play third base for the Cardinals in 2021, Edmundo Sosa, may factor into the team’s plans going forward, it almost certainly will not be at third base. Sosa wouldn’t be the reason the Cardinals would let Nolan Arenado leave town without a fight. But Jordan Walker or Nolan Gorman might be.

Nolan Gorman is a very familiar name to Cardinals prospect-watchers. A 2018 first-round pick out of high school, Gorman has appeared on the annual top 100 prospects lists from Major League Baseball, Baseball America, and Baseball Prospectus in each season since he signed a professional contract. Drafted as a third baseman, Gorman played 77 minor league games as a second baseman in 2021 and received favorable reviews from the Cardinals organization at his adaptability. That said, he is still playing his fair share at third base, and he seems to have the bat to justify it–in 523 MiLB plate appearances, 328 at AAA Memphis and 195 at AA Springfield, Gorman hit 25 home runs and managed a .814 OPS despite not beginning the season at the legal drinking age. He won’t turn 22 until May 10. Baseball Prospectus, typically bullish on Gorman, ranked him 23rd in both 2020 and 2021 among all MLB prospects, and while they marked him a touch lower in 2022, the #28 prospect in all of baseball is a nice thing for Cardinals fans to anticipate.

And then there’s Jordan Walker. Unlike Gorman, whom Major League Baseball estimates should arrive to the St. Louis Cardinals in 2022, Walker is a projected 2024 arrival. After all, he is a full two years younger than Nolan Gorman–born on May 22, 2002, when “Foolish” by Ashanti was America’s number-one song and six days after the release of Star Wars: Episode II–Attack of the Clones, Jordan Walker seems designed to make you feel old. But he also might be a budding superstar.

A 2020 first-round draftee, Walker made his professional debut in 2021, obliterating A-ball pitching with Palm Beach before being promoted to A+ Peoria, where in 244 plate appearances, taken as a young 19 year-old, Walker put together an .831 OPS. Baseball Prospectus, for as bullish as they have been on Nolan Gorman, is even higher on Jordan Walker–Walker ranks #7 on their latest prospect list, behind six guys even I, person who does not claim any prospect expertise, have heard of (Bobby Witt Jr., Adley Rutschman, Julio Rodriguez, Spencer Torkelson, Grayson Rodriguez, Riley Greene). Because it’s hard to contextualize what “#7 prospect in baseball” means, here are some recent examples of #7 prospects per Baseball Prospectus.

• 2021–KeBryan Hayes, Pittsburgh Pirates: Despite only playing in 96 MLB games last season due to injury, Hayes was the fourth most valuable player on the Pirates and won a Fielding Bible Award for third base defense despite playing in the same division as Nolan Arenado.
• 2020–Jarred Kelenic, Seattle Mariners: Kelenic had a rough 2021 MLB debut season–he did hit 14 home runs, but a 73 wRC+ with poor defense in 377 plate appearances is not ideal. That said, a .216 BABIP from a guy who can play center field seems unsustainably low. I certainly can’t declare this a win, but I’m not going to chalk it up as a loss yet either.
• 2019–Forrest Whitley, Houston Astros: Spent 2021 recovering from Tommy John surgery. Has been blocked in one of the strongest organizations in baseball. Is still only 24, despite seeming like he was drafted in 2007. We’ll see.
• 2018–Nick Senzel, Cincinnati Reds: After a stridently okay rookie campaign in 2019, Senzel is starting to be a bit underwhelming. In 616 career MLB plate appearances, he has an 80 wRC+ and has been worth 0.3 fWAR. He’s also 26 and will turn 27 in June. I’m willing to call him a disappointment at this point.
• 2017–Victor Robles, Washington Nationals: Robles looked like a budding superstar during the Nationals’ 2019 World Series run, with superb center field defense and a respectable bat. Over the last two seasons, however, his bat has fallen way off and his glove has been quite a bit more ordinary. In what amounts essentially to two full MLB seasons (1,268 career PA), Robles has an 83 wRC+ and 2.1 fWAR. That said, he’s still only 24. I’m keeping an open mind.
• 2016–Yoán Moncada, Boston Red Sox: Now a Chicago White Sock, Moncada is the first undisputed win of this crop. In 2019, Moncada hit 25 home runs and received MVP votes. In 2021, he coupled solid offense and defense for a 4-win season. Over the last three seasons, only José Ramírez has been more valuable among MLB third basemen.
• 2015–Corey Seager, Los Angeles Dodgers: Since becoming a full-time MLB player in 2016, Corey Seager has been the sport’s 23rd best position player. I would like one of those.
• 2014–Addison Russell, Oakland Athletics: It is essential in this case to separate the massive creep side of Russell (which wasn’t known and thus wasn’t weighed against him at the time) and his production, and while he never became a star in American baseball, he was a pretty valuable player thanks to his defense. Certainly not a Moncada or Seager-level player, but also something short of a bust.
• 2013–Wil Myers, Tampa Bay Rays: 986 games, 3863 plate appearances, 146 home runs, 110 wRC+ but primarily at corner positions rather than his projected center field, 13 fWAR. There may not be a single player in the sport where I have a less conclusive idea of whether he is actually good and I refuse to participate.
• 2012–Jesús Montero, Seattle Mariners: A legendary prospect bust who ranked directly ahead of Manny Machado and Gerrit Cole on this list, he was a sub-replacement level catcher for his career.

So what we have here is…a bit of a mystery. There are some superstars, there are some contributors, there are some busts. Almost all made it to the Majors (though I suspect Forrest Whitley will eventually make it, even if he never lives up to his potential). If the Cardinals believe they have a Yoán Moncada or Corey Seager on their hands in Jordan Walker, and they believe that Walker will stick at third base (an open question at this point), Nolan Arenado suddenly becomes very dispensible.

But this is circling around an unlikely scenario–that Nolan Arenado is enough of a wrecking ball that he would opt out of a $28.8 million per year half-decade, but not so much of one that the Cardinals would move Heaven and Earth to keep him in St. Louis. What the Cardinals do in the most likely scenario–Arenado has a reasonably good 2022 and projects to be a good player in the near-term future, but does not opt out because he would not be able to top 5/144 on the open market–is the more interesting question.

A thirtysomething third baseman under contract until he is 36 years old would generally be a prime candidate for moving down the defensive spectrum, possibly to a corner outfield spot (though given that the single biggest hole in Arenado’s game is his lack of speed, this wouldn’t make too much sense for him in particular) but more likely to first base or designated hitter, the latter which will likely exist in the National League if not in 2022 then within the next few seasons. But defense is such a huge part of Arenado’s game that it is difficult to imagine this transition happening soon. While Arenado’s defensive metrics did slip a little bit in 2021, they are still quite good, and while a 118 career wRC+ for a premium defensive third baseman is quite appetizing, it’s much more pedestrian at first base. Paul Goldschmidt is under contract through 2024, when he will turn 37, and it is reasonable to pencil in Arenado to remain at third base at least through then (and probably longer, but I’ll just say that for now).

If Arenado stays in St. Louis, there are five reasonable infield candidates already in the organization for 2025 (six depending on your level of confidence in Edmundo Sosa). Paul DeJong is the most variable of the five, as his extremely team-friendly contract at the moment will start to get more expensive in the next few seasons, with two team options in 2024 and 2025. Keeping an age-31 Paul DeJong around for 2025 would cost the Cardinals an additional $14 million. The 2017-19 version of DeJong would be worth that–the 5.3 WAR DeJong of 2019 for one season is an auto-accept for the team–but the version of his last couple of seasons, though better than its reputation, is probably not worth keeping around.

Tommy Edman will still be in his final year of salary arbitration and he is coming off a Gold Glove win and has played at a 4+ WAR clip throughout his career. Given his positional versatility (he could play shortstop, though I doubt the Cardinals would pursue this as a long-term plan), he could be a candidate for a pre-arbitration extension if the team sees his floor as being a solid super-utility player. Nolan Arenado is Nolan Arenado, albeit a slightly older Nolan Arenado at that point. And then there is Nolan Gorman, who in this universe would almost certainly be looking to second base as his future, and Jordan Walker, whose position would be a bit more in doubt.

Predicting a 2025 infield feels like a fool’s errand, but given these circumstances, I would guess that Nolan Arenado is still at third base, Nolan Gorman is at second base, either Paul DeJong or somebody I have not yet mentioned is at shortstop, and first base is where Jordan Walker winds up–defense is considered his weakness, and if his bat develops in the way it looks that it might, I wouldn’t consider relegating him to first base even at just his age-23 season to be a bad outcome by any means. And then Tommy Edman floats around the field while the designated hitter spot is used for de facto off-days.

Did you see how quickly I settled into a plan for three seasons from now? I’m creating a lineup card that is roughly as far from today as the Cardinals’ lineup on September 29, 2018, their last meaningful game of that season, in which a solid three starting position players remain on the team today (Yadier Molina, Paul DeJong, Harrison Bader). The Cardinals are loaded for the future in the infield and they may not have enough positions to fill the roles. It’s a lovely problem to have, especially since prospects are fickle enough that there is a less than 50% chance that both Walker and Gorman are future stars, but it’s something to anticipate going forward.

Ultimately, there is nothing the Cardinals can do. I would happily play it safe and flip Jordan Walker for one of the slightly lesser prospects below him on the Baseball Prospectus list that are more coherent positional fits–the next five spots are a starting pitcher, three shortstops, and a catcher–but the Cardinals would almost certainly not get a similar level of prospect in a one-for-one trade. So you keep Walker and Gorman and you dramatically raise the floor of the team’s future infield, and if they all pan out, then your “problem” is a Los Angeles Dodgers-like embarrassment of depth. I wouldn’t say no to that.