49ers' Yetur Gross-Matos: Has successful surgery

Gross-Matos underwent knee surgery Friday, Eric Branch of the San Francisco Chronicle reports.

Gross-Matos was placed on IR on Saturday, so he actually had the surgery before that, although it was not reported at the time. The Penn State product suffered the injury in Week 4 and is expected to miss 4-to-8 weeks, with his earliest availability being Week 10 against the Buccaneers.