49ers' Patrick Willis left game vs. Rams with toe injury; did not return

San Francisco 49ers linebacker Patrick Willis left Monday night's game against the St. Louis Rams with a toe injury and did not return.

Willis has long been one of the 49ers' best defensive players and his injury certainly makes for a big loss with fellow inside linebacker NaVorro Bowman still yet to play this year.

Third-round rookie Chris Borland filled in with the starting unit in Willis' place for the rest of the game.