The host San Diego Chargers will not have star TE Antonio Gates (toe, foot-doubtful) against the visiting San Francisco 49ers this evening for the second game in a row. Journeyman TE Randy McMichael will fill in for him.

The Chargers also will not have starting WR Malcom Floyd (hamstring). Floyd’s lingering hamstring issue flared up in last week’s game. WR Legedu Naanee (hamstring-probable) is the listed starter in Floyd's place. The Chargers will dress just four receivers for the game.

Also out of note for the Chargers are starting G Louis Vasquez (neck), WR Patrick Crayton (wrist) and OLB Larry English (foot).

Vasquez, who missed the previous three games, will be replaced by backup G Tyronne Green for the fourth straight week.

English, a first-round pick for San Diego in 2009, will miss his seventh game this season.

For depth reasons, the Chargers signed LBs Darry Beckwith and Brandon Lang off the practice squad. To make room for them on the 53-man roster, the team waived RB Curtis Brinkley and placed backup S Pat Watkins (knee) on injured reserve.

Beckwith (6-2, 243) is a first-year player from LSU. He spent the ’09 season on the Chargers’ practice squad and was re-signed to that unit on Nov. 24. He has yet to appear in an NFL regular-season game.

Lang (6-3. 266) 24-year-old rookie from Troy University who played in seven games earlier this season. Both Beckwith and Lang made their way to the NFL as undrafted free agents.

Watkins, signed Nov. 15, had played in four games as a gunner and made four tackles on special teams. Brinkley played in two games this season and carried the ball twice for 11 yards. He was inactive the last two games.

The 49ers will be without K Joe Nedney (right knee), who is not expected to play again this season, and starting OLT Joe Staley (leg).

Veteran OT Barry Sims will start his fifth game in a row for the injured Staley. K Jeff Reed will fill in for Nedney.

Starting ILBs Takeo Spikes (hand-questionable) and Patrick Willis (hand-questionable) are expected to be in the lineup.

-- Adam Caplan