What happened to Isaac Guerendo? 49ers RB gets carted off the field after gruesome injury vs. Cardinals in Week 18

On Sunday, the San Francisco 49ers traveled to State Farm Stadium to take on the Arizona Cardinals, looking for only their seventh win of the season. As desperate as coach Kyle Shanahan and his team were to finish the year positively with a victory, their primary objective would have been to escape Week 18 without any of their stars suffering an injury. Unfortunately, that didn't prove to be the case.

Less than two minutes into the game, San Francisco's third-choice running back Isaac Guerendo suffered a left knee injury after it was twisted at an awkward angle under linebacker Kyzir White's body.

Guerendo stayed down, wincing in pain as the 49ers athletic staff rushed to the scene to help the running back. He was eventually carted off. The rookie gave fans inside the stadium a thumbs-up as he left the field. However, he grimaced in pain as he raised his hand before slapping his knees in frustration.

San Francisco is now down to its fourth-choice running back, Patrick Taylor Jr., as Jordan Mason and Christian McCaffrey are also sidelined with injuries.

Isaac Guerendo injury update: RB's impactful season had a sorry end

Shortly after being carted off the field, the 49ers revealed that Isaac Guerendo had suffered knee and ankle injuries. He was immediately ruled out of the game.

The rookie, who featured in 16 games for San Francisco this season, was hoping to cap off his debut year with a stellar display. However, the injury meant he could only add five rushing yards to his tally of 415 rushing yards, four rushing touchdowns, and 15 catches for 152 receiving yards that he entered Week 18 with.

Injuries to McCaffrey and Mason were the reason why Guerendo appeared as frequently as he did. Ironically, his season also ended in being carted off the field. In his absence, Patrick Taylor Jr. led the rushing unit. He carried the ball 17 times for 109 yards but his gritty display had little impact on the final score as the 49ers lost 47-24.