Isaac Guerendo suffered a possible ankle sprain, with further tests to follow on Monday

The 49ers are dealing with another running back injury that could be significant for the team as it prepares to play the Rams on Thursday night.

Isaac Guerendo had to leave Sunday’s win against the Bears due to a foot injury. Although the club called his return questionable, there was no reason to bring him back into the game as San Francisco had a significant lead.

After the contest, head coach Kyle Shanahan said the team was still unsure about Guerendo’s injury and status.

“Possible foot sprain” Shanahan said, via David Bonilla of 49erswebzone.com. “X-rays certainly didn’t show anything, so we’ll have to take a closer look tomorrow.”

Guerendo led the way for San Francisco on Sunday as Christian McCaffrey and Jordan Mason were placed on injured reserve. Guerendo’s day ended with 78 yards on 15 carries, two touchdowns and two catches for 50 yards.

The next replacement would probably be Patrick Taylor, who had 25 yards on seven carries with a 3-yard touchdown on Sunday.

“When we’ve given Patrick runs, whether in preseason or in practice, he’s a good runner,” Shanahan said. “He hits the right spots, he runs hard. So he’s a guy who can definitely help us.”

The 49ers will release their first injury report of the short week on Monday, which will provide further insight into Guerendo’s status for Thursday.