This story was excerpted from Todd Zolecki¡¯s Phillies Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

PHILADELPHIA -- Ranger Su¨¢rez rejoined the Phillies' rotation on Saturday, and he pitched well after missing more than a month because of an injured back.

The Phillies hope it¡¯s just the start. The rotation is four deep again with Zack Wheeler, Aaron Nola, Cristopher S¨¢nchez and Su¨¢rez all healthy. Taijuan Walker is the No. 5 starter, but he has a 6.26 ERA in 13 starts. Philadelphia is 4-9 when he pitches -- it has not won a game he has started since May 22.

Walker¡¯s struggles have become a focal point with the Phils (78-54) fighting the Dodgers (78-54) and Brewers (75-56) for the top two NL postseason seeds. The top two teams get a first-round bye, while the No. 3 seed will play an NL Wild Card Series, making every game critically important down the stretch.

There had been speculation this week that Walker might be pulled from the rotation, based on comments Phillies manager Rob Thomson made over the weekend in Kansas City. But Walker will start Wednesday¡¯s series finale against the Astros.

Thomson said Monday that he was noncommittal about Walker¡¯s next scheduled start only because they had not decided if they wanted to give S¨¢nchez extra rest, which they did.

¡°You can always make a change, but I¡¯m confident that he¡¯s going to bounce back,¡± Thomson said. ¡°Maybe not everybody is, but I am. But that¡¯s who I am.¡±

The Phillies and Walker keep saying that his velocity is going to improve and that his splitter, which is his best pitch, is going to become a dominant pitch again.

The metrics, however, have not been encouraging:

Chase rate vs. Walker's splitter by season
2022 -- 43.3%
2023 -- 34.7%
2024 -- 32.8%

Whiff rate vs. Walker's splitter by season
2022 -- 29.0%
2023 -- 24.4%
2024 -- 16.8%

Because hitters are not chasing Walker¡¯s splitter, he is falling behind in the count more often. Then, when he throws pitches in the zone, he is getting crushed. Of 149 pitchers to allow 200 or more balls in play this season, Walker ranks:

? last?in barrel percentage (14.2%)
? last?in average exit velo (92.1 mph)
? last?in hard-hit percentage (50%)

We know hitters hit better when they are ahead in the count. But hitters are batting an eye-popping .353 with a 1.292 OPS against Walker when they are ahead in the count, compared to .216 with a .547 OPS when they are behind in the count.

Walker¡¯s 1.292 OPS in a hitters' count ranks 178th out 179 pitchers (minimum 60 innings pitched). The .745 difference in OPS when ahead vs. behind in the count ranks 175th out of 179 pitchers.

In 2023, the difference between those two numbers was .424, and in '22 it was .358.

It is why the Phillies have tried to work with Walker on his fastball command before Wednesday¡¯s start.

If there is any hint of a potential turnaround, it might be this: Walker¡¯s splitter¡¯s shape is starting to look more like it did in 2022-23, with less average drop and more average arm-side run.

2022-23
Drop: 32.8 inches
Arm-side run: 11.4 inches

March-July 2024
Drop: 35 inches
Arm-side run: 9.9 inches

August 2024
Drop: 32.5 inches
Arm-side run: 11.5 inches

But Walker has a 9.26 ERA in three August starts, so that change hasn¡¯t helped yet. These overall trends are why folks are wondering about Walker¡¯s future in the organization. Could he be designated for assignment at some point? It is risky to give up on starting pitching, even when a veteran like Walker is struggling.

Plus, Walker is in the second year of a four-year, $72 million contract.

The Phillies haven't swallowed a contract like that, but it is not unprecedented in baseball. The Red Sox designated Pablo Sandoval for assignment in 2017 with about $49 million left on his deal. The Mets DFA¡¯d Robinson Can¨® in 2022, leaving them on the hook for $37.6 million. And the D-backs DFA¡¯d Madison Bumgarner last year, owing him $34 million.

The Phillies said they believe Walker will pitch better. It just needs to happen soon. Too much is on the line.

¡°I think he deserves -- because of who he is and his experience -- he deserves another shot,¡± Thomson said.