PHILADELPHIA -- On the hook for nearly $40 million over the next two years for a pitcher with a 6.50 ERA this season, the Philadelphia Phillies moved Taijuan Walker to the bullpen, turning the 33-year-old right-hander into a long reliever for the stretch run.

Phillies manager Rob Thomson informed Walker of the decision ahead of the opener Thursday of a four-game series with the Atlanta Braves.

Walker (3-6) had not won a game since May 22 for the NL East-leading Phillies and had lost his last six decisions. Walker was tagged for six runs on 13 hits in six innings in a 10-0 loss to Houston on Wednesday. He did not strike out a batter.

The Phillies have lost his past nine starts.

Walker signed a four-year, $72 million deal before the 2023 season.

"The perfect situation would be one inning, low leverage, and then start building from there," Thomson said.

Thomson did not name a new fifth starter for the Phillies, though July sensation Tyler Phillips appears a strong candidate to take Walker's spot in the rotation. The next turn would come Tuesday in Toronto.

Thomson said Walker was a "complete professional" when informed of the decision. Walker is 0-4 with a 9.17 ERA in four starts since he returned from the injured list with a right finger injury.

"I'm hoping his stuff will tick up, the velocity will tick up," Thomson said. "He'll get out there and just pound the ball through the zone."

The 6-foot-4 Walker made the All-Star team for the first time in 2021, putting together a fast start before fading to 7-11 with a 4.47 ERA in 30 games, 29 starts. He's 72-62 with a 4.12 ERA lifetime with the Seattle Mariners, Toronto Blue Jays, New York Mets and Phillies.

"It's tough, you know? It's baseball. Not a lot of things going my way right now, but the biggest thing is trying to keep my confidence, keep going," Walker said after he lost against Houston. "We've got a good team. The offense is really good. Just got to keep trusting in myself."

The Phillies appeared on cruise control toward the NL East title after opening with the best 60-game start of any team since the 2001 Mariners. They slumped through the summer, and their four-game set against the Braves -- a team the Phillies eliminated from the playoffs each of the last two years -- suddenly took on greater meaning. The Phillies held just a five-game lead over the Braves heading into Thursday's game.

"There's a lot on the line for both teams," Thomson said. "A good rivalry. One of the better rivalries in baseball right now. It's going to be a fun weekend."

Thomson pondered whether Walker had "tried to do too much" in his starts because "he knew what was on the line." The third-year manager insisted Walker -- who won 15 games a year ago but did not pitch in the postseason as the Phillies reached the NL Championship Series -- was not injured.