Avila (knee) underwent successful knee surgery Thursday, Adam Grosbard of The Orange County Register reports.
Avila suffered a sprained MCL in the Rams' season-opening loss to Detroit and landed on IR on Wednesday. It's not clear exactly how much time he'll miss, but the offensive lineman will need to sit out at least the Rams' next four games. Jonah Jackson will likely slide over to left guard while Beaux Limmer takes over at center.