Phillies place Taijuan Walker on 15-day injured list

The Phillies announced this morning that they have been drafted right-handed Taijuan hiker on the 15-day injured list due to an inflammation in his right index finger. Right-handed Michael Mercado was recalled to the majors in a corresponding move. Mercado’s first appearance will be his big league debut.

Walker, 32 in August, has had a rough 2024 season as he dealt with both injuries and ineffectiveness. A shoulder impingement delayed his season debut until late April, and he has struggled significantly in ten starts since then. The righty has a 5.60 ERA and 5.77 FIP on the season, numbers that are 37% and 40% worse than league average, respectively. Only two of Walker’s 10 appearances have been quality starts, and opponents have hit an eye-popping .278/.353/.511 against him in seven starts dating back to May 16. In other words, Walker’s opponents have been beaten off in recent weeks. to achieve results roughly comparable to those of the Guardians star Jose Ramirez (.271/.330/.528) has posted this season.

Walker’s struggles came to a head on Friday night against the Diamondbacks, when the righty allowed four runs on five hits and three walks in just four innings of work while striking out just three batters. Manager Rob Thomson told reporters yesterday (as noted by MLB.com’s Injury Tracker) that Walker was dealing with a “hot spot” on his finger and suggested the problem “has probably been going on for a while.” Thomson specifically suggested that the injury may have affected the efficacy of Walker’s splitter. The splitter was Walker’s most used pitch last year, when he threw it 33.2% of the time, according to Statcast. That usage has dropped to just 17.4% in 2024, and MLB.com notes he has thrown just 16 total throws in his past two starts.

That decline in use corresponded to a decline in efficacy. In 2023, opponents hit just .205 against Walker’s splitter, with a .295 slugging percentage and a .257 wOBA. These strong results are a far cry from what the right-hander has produced with the pitch this year, as opponents have hit as much as .426 with a .704 slugging percentage and a wOBA of .477. That .426 mark is the highest average Walker has allowed on any pitch this year, in stark contrast to last year, where his splitter had a lower average against than any pitch in his repertoire except his rarely used sweeper .

Considering that Walker’s finger problem has seemingly affected his ability to throw his most important pitch, it’s no surprise that the right-hander has experienced such extreme issues so far in the season. Going forward, the Phillies will sit out the righty for at least the next two weeks to give the inflammation time to settle down. It’s certainly a pretty easy decision for Philadelphia not to let Walker continue to try to solve the problem, given the presence of a right-hander Spencer Turnbull. Turnbull has been outstanding for the club this year while bouncing between the rotation and the bullpen, posting a 2.63 ERA and 3.57 FIP in 51 1/3 innings across 16 appearances (six starts).

Although Turnbull hasn’t started a game since late April, the righty threw 49 pitches in his most recent outing on Friday and believes he can step into the rotation and provide the Phillies with solid production in Walker’s place. That leaves the long relief role of the bullpen to Mercado, who will replace Walker on the club’s roster. Mercado was the Rays’ second-round pick in the 2017 draft but did not appear at the big league level with the club before being traded to the Phillies in November. Philadelphia quickly placed Mercado on their 40-man roster and sent him to Triple-A to open the season, where he excelled with a 1.71 ERA and a 22.8% strikeout rate in 47 1/3 innings of work split between the rotation and the bullpen at the level.