Fred Warner, the San Francisco 49ers All-Pro linebacker, suffered a serious and gruesome ankle injury during a game against the Tampa Bay Buccaneers.

The injury occurred in the first quarter when Warner was rolled up on by safety Ji’Ayir Brown while attempting a tackle. This caused a severe ankle fracture dislocation, and Warner had to be carted off the field with his right leg in an air cast.

The injury is significant enough that Warner is likely out for the season. The 49ers bench showed visible concern, and his absence is a major blow to the team, who are already dealing with other key injuries