The San Francisco 49ers are going to have a fourth different starting running back this season according to a report from ESPN’s Adam Schefter.

Running back Isaac Guerendo suffered a hamstring injury in the 49ers’ Week 15 loss to the Los Angeles Rams and is unlikely to suit up Sunday for the team’s Week 16 matchup against the Miami Dolphins.

Guerendo was absent from Wednesday’s practice because of the injury.

It’s the second consecutive game the 49ers rookie RB has suffered an injury. He also hurt his foot in Week 14 against the Chicago Bears and was questionable to play in Week 15. He put together a strong outing on the short turnaround to Thursday night, but exited the contest with a new issue.

Guerendo played in only 41 games across five college seasons in part because of injuries. This is the second time as a rookie he’s missed time with a hamstring ailment. He also missed almost all of training camp with the same issue.

With Guerendo out, the 49ers will likely turn to RB Patrick Taylor who has been the backup with Guerendo starting. San Francisco also has Israel Abanikanda who they acquired off waivers from the New York Jets after RBs Christian McCaffrey and Jordan Mason went down with injuries. Ke’Shawn Vaughn is also on the practice squad and may get promoted to the active roster if there’s a player the 49ers wind up placing on IR with three weeks to go.