The Redskins have placed Lorenzo Alexander on injured reserve, ending the defensive tackle's season.

Alexander suffered a hamstring injury in the Dec. 21 game against the Philadelphia Eagles.

Alexander would not be available for the Redskins' season finale against San Francisco, so the team opted to place him on injured reserve to open up a roster spot.

He finished the season with 26 tackles, two sacks and two passes defended.

It's a tough break for Alexander. He hails from Berkeley, Calif., so Sunday's game against San Francisco would have been a homecoming for the third-year pro.

To fill Alexander's roster spot, the Redskins signed linebacker Tyson Smith.

The 6-2, 250-pound Smith was on the Redskins' practice squad in 2006. He has also had stints with the Denver Broncos, Miami Dolphins, San Francisco 49ers, New York Giants, Dallas Cowboys and Baltimore Ravens.

Smith played college football at Iowa State. He hails from West Des Moines, Iowa.