49ers' Christian McCaffrey Supports Teammate After ‘Unfortunate' Injury

On Thursday, San Francisco 49ers head coach Kyle Shanahan revealed troubling news for third-year running back Isaac Guerendo.

Guerendo suffered a pectoral injury while lifting weights approximately a month ago. The 49ers do not anticipate the running back missing most of the regular season, but he’s expected to miss at least the majority of training camp this summer.

Veteran running back Christian McCaffrey sent strong words of support to Guerendo, saying he had been “working his butt off” this spring before suffering the “unfortunate” injury.

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“Sometimes, this game is super unfortunate,” McCaffrey said, via 49ers Webzone. “He was working his butt off all offseason, and sometimes it’s that freak stuff that happens, where you strain something training in the weight room or something. It’s unfortunate, but he’s got the best attitude.

“He’s coming in every single day with a smile, still working just as hard, and it’s not a season-ending injury. He’ll be back, so it’s also perspective. As much as he’s down, he knows that he will be back for the season, so I think there’s also some enthusiasm there.”

It’s unclear if the injury happened before or after the draft, but the timeline Shanahan provided might explain why the 49ers took running back Kaelon Black in the third round. The 49ers plan to decrease McCaffrey’s workload in the regular season, and the team needs a stable of running backs to stay fresh.

With Black in the backfield, Guerendo will face more pressure when he returns to the 49ers. Guerendo, 25, was a fourth-round pick by San Francisco in 2024. He rushed for 420 yards and four touchdowns as a rookie in addition to being a return man on kickoffs.

Guerendo appeared in 14 games last season but recorded no stats on offense, primarily finding work on special teams. He played in 49 percent of the 49ers' special teams snaps.

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This story was originally published May 28, 2026 at 6:28 PM.