Which starters should the Cardinals extend?

The mass exodus facing the Cardinals rotation at the end of the 2023 season is well-documented at this point. Longtime rotation stalwart Adam Wainwright is set to follow in the footsteps of his longtime battery-mate Yadier Molina and retire following the end of the 2023 season, while each of Miles Mikolas, Jack Flaherty, and Jordan Montgomery are set to depart the club as free agents. If none of that group is extended, right-hander Dakota Hudson will be the only pitcher to make more than ten starts with the Cardinals in 2022 and remain with the club in 2024, though lefty Steven Matz is also under contract through the 2025 season and youngster Andre Pallante impressed in ten starts last season.

The 2023-2024 free agent class figures to be exceptional deep in quality rotation options, even for clubs who won’t be part of the Shohei Ohtani sweepstakes. Still, it seems reasonable to expect extensions, such as the one Yu Darvish signed with the Padres last week, to continue thinning the herd throughout Spring Training and into the regular season. For a Cardinals club that’s attempting to make the most of the remaining prime years for superstars Nolan Arenado and Paul Goldschmidt, going into the offseason with three or more slots in the rotation to fill would put an enormous amount of pressure on the front office. As such, it’s no wonder that the organization is reportedly planning to have extensive conversations with at least two of their starting pitchers this spring.

The clearest choice for the Cardinals to pursue an extension with would be Mikolas, who reportedly is open to extending with the club this spring. Even entering his age-34 season, there’s every reason to expect Mikolas to be durable going forward; though he missed the entirety of the 2020 season and much of the 2021 season due to surgery, since joining the Cardinals ahead of the 2018 season he has pitched more than 180 innings in each of his three seasons unaffected by that surgery, including inning counts over 200 innings in 2018 and 2022. On top of that, Mikolas has proven to be an effective mid-rotation option whenever he is on the mound, with a 3.46 ERA (114 ERA+) and a 3.84 FIP in 631 2/3 innings as a member of the Cardinals.

Furthermore, despite his age and workhorse tendencies, the mileage on his arm is still fairly low: Mikolas has just 1,561 professional innings under his belt between the majors, minors, and his time overseas. That’s more than a thousand innings less than similarly aged hurlers such as Yu Darvish and Clayton Kershaw, and just a tad under the 1,746 1/3 professional innings Aaron Nola has under his belt headed into his age-30 season. Given Mikolas’s combination of effectiveness, durability, low mileage on his arm, and comfort with the club (he already extended with the team once, ahead of the 2019 season), it’s no wonder that Mikolas appears to be one of the starters the Cardinals are seeking to continue their partnership with.

What of the other options, though? Surely, if Wainwright changes his mind and decides to continue pitching in 2024, the lifelong Cardinal would be continuing his career in St. Louis. All signs point to him hanging them up this fall after the conclusion of his age-41 season, however, leaving two pending free agents in the Cardinals rotation for them to consider extending: Flaherty and Montgomery. Flaherty is the younger of the two, set to pitch in 2023 at age 27 while Montgomery celebrated his 30th birthday earlier this offseason. Both players have dealt with injury woes in their careers, though Flaherty’s are more recent, having spanned the 2020-2022 seasons. Montgomery’s struggles from 2018-2020, by contrast, have since been followed up by a pair of quality, healthy seasons.

Montgomery has also shown more consistency throughout his career; when healthy, he has reliably been good for around 150 innings of 10-15% better than league-average baseball. Flaherty, on the other hand, has two exceptional seasons under his belt in 2018 and 2019 where he combined for a 3.01 ERA, 35% better than league-average, while finishing top 5 in Rookie of the Year voting in 2018 and Cy Young award voting in 2019. Outside of those two seasons, however, he has just 176 career innings at the major league level under his belt, and the results of those innings leave much to be desired: a 4.19 ERA and more than a strikeout less per nine innings than his peak years.

One can rightfully argue that Flaherty, so long as he can get healthy, projects to be better than Montgomery going forward. Montgomery’s fastball velocity in 2022 clocked in just below that of Flaherty despite the fact that Montgomery was enjoying a career-high while Flaherty’s velocity was at an all-time low. Flaherty’s camp will surely make that argument, and with such a considerable gap between Flaherty’s potential and his current results, it’s fair to wonder how feasible it is for the two sides to come together on an extension they both find mutually agreeable, particularly when a big season from Flaherty in 2023 could cement him among the top starters on next offseason’s free agent market. Flaherty seems, perhaps, particularly unlikely to take much of a discount given he forced St. Louis to renew his contract ahead of both the 2019 and 2020 seasons rather than agree to a pre-arbitration salary, calling it a matter of “principle.”

The Cardinals have no such contentious history of negotiations with Montgomery, whom they acquired at the trade deadline last season in a deal that sent center fielder Harrison Bader to the Yankees. Montgomery pitched extremely well down the stretch for St. Louis last season, racking up 63 2/3 innings that were good for a 3.11 ERA (123 ERA+) and a 3.08 FIP. While Montgomery’s potential is far from that of Flaherty, that dominant stretch to end the 2022 season could indicate that there is still upside yet to be tapped into for the left-hander. Furthermore, despite not being a member of the organization for very long, that hasn’t stopped this Cardinals front office in the past. After all, president of baseball operations John Mozeliak is the one who signed Goldschmidt to an extension prior to the 2019 season before the slugger had ever played a regular season game in a Cardinals uniform.

Financially speaking, the Cardinals have plenty of room to maneuver under the luxury tax going forward. The club’s estimated luxury tax payroll for 2024 according to Roster Resource is just over $106MM, down from $199M in 2023. Granted, that 2024 figure does not include arbitration salaries for 2024. In 2023, arbitration salaries are adding $36.5M to the luxury tax ledger in St. Louis- even if that figure repeats, the club would have nearly $60M to play with before reaching their 2023 payroll level and over $90M before reaching the first luxury tax threshold. That should leave them Mozeliak’s front office plenty of room to add or extend starters ahead of the 2024 season.

For players between five and six years of service time, as Flaherty and Montgomery both are, three recent extensions have taken place: the seven-year, $131M deal Jose Berrios signed with the Blue Jays last offseason, the five-year, $100M deal Joe Musgrove signed with the Padres last summer, and the five-year, $85M deal Lance McCullers Jr. signed with the Astros ahead of the 2021 season. Berrios stands as something of a clear outlier among the other two, while Joe Musgrove has been a more effective starter than Montgomery and a more consistent starter than Flaherty. As such, McCullers seems to be the most appropriate comp for our purposes.

McCullers and Montgomery both are solid mid-rotation starters when healthy, and though McCullers was just about to begin his age-27 season when he signed his extension, making him three years younger than Montgomery is now, he was coming off far more recent injury troubles than Montgomery was while having never pitched even 130 innings in a season of his career. The $85M figure also compares reasonably to the mid-rotation market this past offseason, which each of Chris Bassitt, Jameson Taillon, and Taijuan Walker securing between $63M and $72M and Montgomery having an argument as a safer bet than any of them.

Flaherty, on the other hand, seems less likely to find that sort of deal appropriate. Following an offseason that saw the likes of Carlos Rodon and Jacob deGrom secure well over $100M despite injury concerns, it’s reasonable to think that Flaherty could do the same with relative ease should he have a bounceback year in 2023, particularly given his youth. Additionally, the market was rather kind to even oft-injured bounceback types such as Andrew Heaney this offseason. Even if Flaherty struggles again in 2023, he could search for a two-year deal with an opt-out as Heaney did to rebuild his value and hit the market a second time before his age-30 season.

Given all of this, it seems unlikely he would settle for much less than the $100M Musgrove received, and it seems even more unlikely the Cardinals would make such a risky investment at this point, even with their significant concerns about the future of their rotation. Taken together, it seems that if the Cardinals are going to look to lock up some of the members of their rotation before season’s end, they’d be better off looking toward Mikolas and Montgomery than Flaherty, even despite all the tantalizing talent he brings to the table.