With his rehab appearance on Sunday, Taijuan Walker is coming back to the majors. The Phillies appear to have been able to negotiate that Walker make another appearance to work up to 100 pitches. It wasn’t pretty or inspiring, but he did accomplish that task. Meanwhile, his replacement, Spencer Turnbull carried a no-hitter into the 7th inning, another in a line of successful starts in Walker’s place in the rotation. Turnbull will get another start this week (a rematch with the Reds), before the Phillies will have to finalize their decision.
On the spectrum of problems a team can have, having 6 healthy starting major league pitchers is among the lowest acuity. Add in that this is really only a discussion between Walker and Turnbull because the entire major league rotation has been dominant really puts into perspective that this much about not wrecking the good times as it is anything else. Much of the vitriol stems around Taijuan Walker because he is the interloper on the happy little story that is Turnbull, so it is probably best if we start with Turnbull.
What Spencer Turnbull is currently doing is unsustainable. That isn’t to say he is secretly bad, but it is important that we acknowledge there is a sheen on his numbers that we would not expect to continue even if Walker wasn’t here. He currently has a 1.23 ERA, but he has a 2.89 FIP and a 4.27 DRA. Much of the discrepancy being driven by a .167 BABIP against and minuscule 5.6% HR/FB rate. He has also faced the Reds, Cardinals, Pirates, and White Sox, not necessarily a bunch of great lineups. His new sweeper and four-seam fastball shape grade out very well, so this is definitely not smoke and mirrors, it just might be more mid rotation than undiscovered ace.
Then there is the unsustainability due to workload. Turnbull has a starting pitcher frame, but due to injuries and other factors he has not pitched more than 60 innings in a season since 2019. At best, you would expect a fatigue period, and at worst catastrophic injury. We saw in 2023 that Matt Strahm gradually wore down before his move back to the bullpen. There was a very slim chance that Turnbull was going to run through the full season health and effective.other teams might just run a guy until he breaks, but that has not been the Phillies over the last few years.
Which really gets to the most important part of both pitchers. The Phillies need both of them as starting pitchers. At some point this season another starting pitcher is going to get hurt or ineffective (it might even be Walker), and then Turnbull should step right back into the rotation. Any move from rotation to bullpen for Turnbull should be viewed in that temporary light.
On the Taijuan Walker side of things it starts with it being in the Phillies best interest that Walker can be a competent starting pitcher. That starts with the Phillies maintaining enough starting pitcher depth to navigate the season. He also has nearly 3 years left on his contract, and while much of that is sunk cost, getting value from Walker either on the Phillies or from a trade requires that Walker pitch for them. Burying him in the bullpen without giving him a start could be disastrous for any relationship between player and team, and leave the Phillies in a bad position if there is a future injury or issue.
The idea that Walker may be a competent starting pitcher is not that far off of reality given that is what he was in aggregate during the 2023 season. Walker’s contract, inconsistency, and lack of appearance in the postseason, have largely obscured the number of innings (172.2) he pitched and his success at his peak (2.58 ERA in 11 starts, 66.1 IP, in June and July). It is very fair to say that Walker has not lived up to the contract, but that is different than saying he is not a major league caliber starting pitcher. Most advanced metrics were actually fairly complimentary of his year with Baseball Reference having him at an ERA+ of 100 and 2.5 WAR, the FIP based Fangraphs also had him at 2.5 wins, and Baseball Prospectus’ WAR coming in at 1.5, not far off his previous two seasons.
All of this leads to the rock and hard place that the Phillies find themselves in. Walker has made it clear he thinks he is healthy and has cleared the rehab innings benchmark the Phillies laid out for him. The Phillies must now activate him from the injured list – not activating him risks a grievance and further degradation of the relationship between team and player. Complicating all of this has been Walker’s rehab, where he has clearly not been throwing as best as he can. In his latest rehab start, his fastball mostly sat below 90 mph in not ideal conditions, but definitely not bad enough to suppress his velocity that much. This makes it hard to know where he actually is heading into the season, is he going to be 90-92 and a real liability, or does the adrenaline of a major league mound push him higher.
For now, the long term play is to give Walker some rope and to give Turnbull some rest. The bullpen has a natural spot where Ricardo Pinto is for a multi inning reliever. There is every reason to believe that Turnbull can be a weapon like Strahm was last year, and it leaves the bullpen for now with very few weak points (a scuffling Seranthony Dominguez is probably the most pressing). If Walker continues to struggle there is now data points to work with to say that the team has a better option and a switch is worth it. If he actually goes out and is a solid starting pitcher, the Phillies can just wait with their depth for the inevitable hammer fall, and enviable position for a playoff contender.