San Francisco 49ers offensive tackle Joe Staley sustained a sprained MCL in the team's Week 13 win over the St. Louis Rams. He will undergo an MRI to determine the injury's severity, according to Matt Barrows of The Sacramento Bee.
Staley's injury is the next in a long line for San Francisco in 2013. It's unclear whether he'll be forced to miss time, but Niners Nation notes that it's encouraging the Pro Bowl left tackle was able to leave the field under his own power.
The good bit of news about Staley was that he was seen walking without assistance. When he tried putting extra weight on the leg on the sideline he was in pain, but it's certainly better than requiring assistance to get around.
It's unclear how head coach Jim Harbaugh will shuffle the offensive line if Staley is forced to miss time. The unit is already lacking right guard Mike Iupati, who continues to recover from a sprained MCL of his own, while the team could continue to lean on Alex Boone. He moved from offensive guard against the Rams, and played well in a reserve role.
The injury isn't dissimilar to one Staley sustained earlier this season where he was taken for X-rays. San Francisco will hope the injury is of a similar nature, where it was not serious and he returned to action quickly.