PHILADELPHIA -- Just as Taijuan Walker seemed to be settling back into the Phillies' starting rotation, his status is suddenly once again up in the air.

Walker departed in the fourth frame of Thursday night's 6-5, 11-inning loss to the Mets at Citizens Bank Park with a left big toe contusion after being struck by a 99.7 mph line drive off the bat of Starling Marte. Though Walker initially feared the worst, X-rays were negative.

“It feels better now than when it first happened,” Walker said. “I tried to walk it off a little bit, but it kept getting kind of hot and numb -- just started hurting.”

Whether Walker will be ready for his next turn through the rotation remains to be seen.

"We'll just have to see how he comes in tomorrow," manager Rob Thomson said. "Don't know about his next start, but we'll find out a little bit more tomorrow."

Making just his fourth start after missing the first month of the season, Walker allowed two runs off four hits and two walks while striking out one over 3 1/3 innings. The final of those four hits was a laser off the bat of Marte that ricocheted high off Walker's foot to second baseman Whit Merrifield for an infield single.

Thomson and a club trainer came out to check on Walker, who said he was unable to put any weight on his left foot. After limping down the dugout steps and up the tunnel, he admitted he was nervous to even take off his sock because he was worried about the possible extent of the injury.

“It’s definitely sore, bruised, starting to swell a bit,” Walker said. “But could have been a lot worse.”

It's been a tough stretch for Walker, who didn't make his season debut until April 28 due to right shoulder soreness that popped up in the final week of Spring Training. That came after he missed time at the start of camp due to personal reasons and right knee soreness.

Walker's recent return forced Spencer Turnbull to the bullpen, despite Turnbull filling in admirably with a 1.67 ERA over six starts.

The Phillies have done their best to keep Turnbull stretched out in relief in the event they eventually needed to move him back to the rotation. His most recent outing came in Wednesday's 10-5 win, when he tossed 54 pitches over three innings of three-run ball.

If Walker can’t make his next start, Turnbull would be available on extra rest to slot back into that rotation spot. Another option would be to simply skip Walker’s spot the next time through -- made possible by Monday’s off-day -- which would give him some extra time without necessarily landing on the injured list.

Pitching in the second season of a four-year, $72 million deal, Walker’s time in Philadelphia has certainly had its ups and downs. He won a team-leading 15 games while posting a 4.38 ERA over 31 starts last season, but he didn’t throw a single pitch in the 2023 postseason -- largely due to concerns over his diminished velocity.

Of Walker's 11 starts with his slowest average fastball velocity from 2013-23, nine came last season, including eight after the All-Star break. So Walker reported to camp this spring intent on getting more consistent with his velocity, but that simply hasn't been possible with the repeated disruptions.

“Definitely, it is frustrating,” Walker said. “I tried so bad to go throw a pitch and just see how it felt, but couldn’t. I'm very frustrated about it, because I feel good [otherwise].”

The latest injury came on a night when there were some encouraging signs.

With two on and one out in the second inning, pitching coach Caleb Cotham made a trip to the mound to relay a simple message to Walker: Trust your splitter. Though it’s been Walker’s go-to pitch over the past couple of seasons, he admittedly hasn’t had a feel for it in his first few starts.

Walker responded by throwing a splitter for a called strike, then throwing another to induce an inning-ending double play.

“I thought his split was as good as he's had -- or better than he's had -- all year, and the fastball had a little more life,” Thomson said. “I could see the life coming back to his fastball.”

That only makes the fluke injury all the more frustrating for Walker.

“I thought my splitter started coming back a little bit, so I felt really good with that and started throwing it more,” Walker said. “And then this happens. Again, I'm glad it's not broken. Guess it's just kind of day to day.”