Patrick Willis out for rest of season

— -- San Francisco 49ers linebacker Patrick Willis will miss the remainder of the season and needs surgery for his strained left big toe.

The team placed him on season-ending injured reserve Tuesday and filled his roster spot by signing running back Alfonso Smith to a one-year contract.

A seven-time Pro Bowler, Willis has missed the past three games for San Francisco (5-4) after injuring the toe in the third quarter at St. Louis on Oct. 13. He had 34 tackles and an interception this season for the Niners, who have reached the NFC Championship Game in each of the past three seasons.

Willis had hoped the injury wouldn't sideline him long term. He missed practice last week after returning in a limited role the previous week.

After resting through the Oct. 26 bye, Willis was back as part of the 49ers' full active squad on the field for the start of practice Oct. 29, but he had been limited primarily to individual work.

This is a big loss to one of the NFL's leading defenses, although the 49ers are expected to have Aldon Smith back Sunday on the road against the New York Giants.

Smith is set to begin practicing this week after serving his nine-game suspension by the NFL for violations of the league's substance-abuse and personal-conduct policies.

In addition, 2013 All-Pro NaVorro Bowman could be cleared to begin practice this week, opening a 21-day window for the team to activate him or place him on injured reserve.

Bowman is recovering from surgery on his left knee after he tore the ACL and MCL in a devastating injury in the NFC Championship Game loss at Seattle this past January.

Rookie Chris Borland has filled in for Willis and been spectacular, recording 18 tackles in a loss to the Rams two weeks ago, then 17 more tackles in an overtime win at New Orleans on Sunday.

The Associated Press contributed to this report.