PHILADELPHIA -- Taijuan Walker is no longer a starter for the Phillies.

He will be a long man in the bullpen through September. His future beyond that, however, is cloudy at best.

Phillies manager Rob Thomson said prior to Thursday's series opener against the Braves that Walker has been bumped from the rotation following his latest poor start in Wednesday's 10-0 loss to the Astros. Walker allowed 13 hits and six runs in six innings against Houston. He is 3-6 with a 6.50 ERA in 14 starts this season, including 0-3 with a 9.17 ERA in four starts since he returned from the injured list on Aug. 13.

The Phillies have lost each of his last nine starts.

Rookie right-hander Tyler Phillips is most likely to take Walker’s spot on Tuesday in Toronto, although no announcement has been made. Left-hander Kolby Allard has pitched well, but he is not eligible to be recalled from Triple-A Lehigh Valley until Sept. 10, barring an injury.

The Phillies hope Walker will pick up a few innings here and there, but they do not know if he will be more effective as a reliever.

“Well, I'm hoping he will be,” Thomson said. “I'm hoping his stuff will tick up -- the velocity will tick up -- and he'll get out there and just power the ball through the zone. So, we'll see.”

There had been speculation that Walker could be designated for assignment, but he is in the second year of a four-year, $72 million contract. If the Phillies had DFA’d him on Thursday, they would have owed him approximately $39 million.

The Phillies have never come close to swallowing a contract like that. Other teams have. The Red Sox DFA’d Pablo Sandoval in 2017 with approximately $49 million left on his deal. The Mets DFA’d Robinson Canó in 2022 with about $37.6 million owed. The Astros DFA’d José Abreu earlier this season with $30 million remaining on his contract. The Diamondbacks DFA’d Madison Bumgarner in 2023. They owed him $34 million.

But Thomson indicated they still believe Walker can be a viable starter at some point.

It won’t happen until 2025, at the earliest -- if he remains in the organization.

“I feel for him because he's put so much time and effort into this thing,” Thomson said. “He's worked extremely hard. Long toss, weighted balls, light balls -- all kinds of stuff. He's not the same guy that he was. And, hopefully, with work over the offseason and the rest of the season, we get that velocity back and that stuff back.

“The program that he was on to try and gain velocity, we didn't have enough time. Like, that program's a long program, and we sort of cut the program off early. I think if he has a full offseason of that program, we got a better chance of seeing some improvement.”

The Phillies are locked into their top four rotation spots heading into 2025 with Zack Wheeler, Aaron Nola, Ranger Suárez and Cristopher Sánchez.

No. 1 pitching prospect Andrew Painter could be in the mix at some point next year. He is progressing well from Tommy John surgery. He recently experienced general soreness often experienced by pitchers recovering from the procedure, but he threw a bullpen session on Thursday in Clearwater, Fla.

Still, it is unclear if Painter will be ready to compete with other pitchers in Spring Training or if he will need more time. But Spring Training 2025 is the furthest thing from Thomson’s mind for the time being.

Thomson said whoever starts Tuesday in Toronto will likely make two starts before the Phillies reevaluate the situation. The No. 5 starter is expected to make five more starts before the end of the season. Those five games could determine the Phillies’ postseason seed.