PHILADELPHIA -- The Phillies dealt with an injury scare for the second straight game on Sunday night -- but they may not be as fortunate this time around.

One night after left-hander Ranger Su¨¢rez seemingly avoided a major injury after taking a comebacker off his pitching hand, outfielder Brandon Marsh departed a 5-4 10-inning loss to the Cardinals at Citizens Bank Park with a strained right hamstring. Marsh immediately signaled for the training staff while grabbing the back of his leg after attempting to round second base in the bottom of the eighth inning.

He was still undergoing treatment following the game and was not available to the media.

"We don't know, really; we'll find out tomorrow," manager Rob Thomson said when asked about the extent of the injury. "They'll look at it tomorrow. He's day to day -- at this point."

Though Thomson and the Phillies remain hopeful that Marsh -- like Su¨¢rez -- can dodge a bullet, it was evident that Marsh was in a lot of pain. Television replays appeared to show Marsh initially grimaced as he rounded first base on his leadoff single in the eighth, but the injury became obvious one batter later.

As Marsh rounded second on Nick Castellanos' ensuing single, he suddenly reached for his right leg before quickly retreating to the base as he waved the team trainer out of the first-base dugout. As soon as Thomson reached Marsh at second, the skipper turned back toward the dugout and called for a pinch-runner.

"I just saw it in his face," Thomson said. "He was in pain."

The extent of hamstring strains can vary significantly. Some don't even require an IL stint, while others can drag on for a couple months.

That's no secret to a Phillies team that has been without shortstop Trea Turner since May 3 due to a left hamstring strain. Turner originally said that returning in anything less than six weeks would be a "win." Though he continues to progress following a setback last week in Colorado, there's still no firm timetable for Turner to head out on a rehab stint.

If the Phillies indeed need to replace Marsh for any amount of time, they will have a few different options. Cristian Pache would provide elite defense in left, but he's hitting just .216 this season and is mostly considered a platoon option against left-handers.

A potential opening could also provide the club a chance to give Kody Clemens, or possibly even Edmundo Sosa, a look in left field. Clemens, however, is also day to day after being scratched 90 minutes before first pitch due to back spasms. Thomson has said at various points over the past week that he wouldn't rule out the possibility of trying Clemens or Sosa in the corner outfield spots in an attempt to keep getting them reps once Turner returns.

Whit Merrifield would also be a candidate to play left field -- the position he's started at more than any other this season. Of course, he's hitting just .176 with a .532 OPS in his limited opportunities after going 0-for-4 with a strikeout on Sunday.

"That's the issue: Just because he hasn't played, I think that's the problem," Thomson said. "So we've got to try to, somehow, get him some more playing time."

Marsh's injury capped off what was a rare off night for a Phillies team that lost for just the second time in its last 24 home games.

Right-hander Taijuan Walker gave up four runs on five hits ¨C including a pair of two-run home runs ¨C and three walks over five innings. His season ERA jumped to 5.73 as he continues to search for consistency after missing the first month of the season.

¡°He left the ball up a couple times, two home runs,¡± Thomson said. ¡°I think he just needs to command better and needs to keep the ball down. And he knows that. Just need to keep working at it."

The Phillies bailed out Walker by rallying twice from a two-run deficit, but they couldn¡¯t come through with a clutch hit. They went just 3-for-17 with runners in scoring position, including 0-for-3 in the eighth after Marsh departed with runners on first and second with nobody out in a 4-4 game. Philadelphia also went 0-for-3 in the 10th with the automatic runner on base.

Those uncharacteristic missed chances don¡¯t figure to be a long-term concern. The questions surrounding Marsh and Walker likely loom larger.

¡°It's just frustrating,¡± Walker said. ¡°Obviously, the team is playing so well right now and I just want to be a part of that and help the team, but I'm just not doing my part right now.¡±