Jimmy Garoppolo could be without one of his main protectors in Trent Williams when the San Francisco 49ers play the Miami Dolphins in Week 13.

Williams reportedly left Friday's practice and walked back into the locker room due to some back issues, putting his availability for Sunday's game in limbo. He has since been listed as questionable as the 49ers let him rest.

According to head coach Kyle Shanahan, Williams suffered from back spasms. However, he played down the severity of the issue and noted that he would have been concerned had the Pro Bowler sustained it on gameday.

“I'm not too concerned. Asked [offensive line coach] Chris [Foerster] if he’s alright and he said it’s big-guy problems. If you have [back spams] on game day, it’s a big deal. Had them today, so he will spend the day resting,” Shanahan said of Williams' condition.

Sure enough, hopes are high that Trent Williams won't need to be sidelined against the Dolphins because of the issue. With the 49ers looking to maintain the top spot and possibly widen the gap against the Seattle Seahawks in the NFC West, they really cannot afford to lose games at this point of the campaign.

The good news for Jimmy Garoppolo and the 49ers is that Williams doesn't have any history with back issues. This season alone, he has only missed three games (from Weeks 4 to 7) due to an ankle injury. He has started every other game aside from those matches he missed.

Williams still has more than 24 hours to rest his body, and fans will likely know more about his official status come Saturday.