With C Rudy Niswanger not likely to play against San Diego after injuring the same knee for a second straight week last Sunday in Denver, replacement guard Wade Smith will move over to center, as he's done in the last two games when Niswanger went down (before later returning).

But instead of asking second-year tackle Herb Taylor to play right guard when Smith moved to the center, the Chiefs likely will have full-time starting RG Adrian Jones back in the lineup this week after missing the previous four games with an ankle injury.

Smith has been battling injuries of his own the last couple of weeks, though he's played through them. If he were to go down this week, Pro Bowl left guard Brian Waters would have to snap.

PLAYER NOTES

--C Rudy Niswanger did not practice for a second day Thursday and doesn't appear likely to play against San Diego. Wade Smith will move from right guard, where he has started the last four games, to center.

--RG Adrian Jones is expected to return to his starting position after missing the previous four games with an ankle injury. He has had full workouts on both Wednesday and Thursday.

--CB Pat Surtain did only limited work again Wednesday, which isn't good as the Chiefs could really use him this week with rookie nickel back Maurice Leggett questionable with a shoulder injury. Surtain, a veteran starter in the first two games, has played in only five games this season -- with very limited participation in several -- while nursing a quad injury.

--CB Maurice Leggett's string of touchdowns in his last two games -- one on a special teams return, the other on an interception return last week in Denver -- looks in jeopardy after he was limited in a second workout Thursday with a shoulder injury.

--LB Pat Thomas appears ready to return to action after missing the previous four games with a hamstring injury. He's had full participation in the past two workouts, but when he returns it will be as a reserve as Derrick Johnson has been moved into his Mike backer position.

--RT Damian McIntosh did not practice Thursday while battling an illness, but the Chiefs think he'll be playing this week against San Diego.

--WR Mark Bradley, who had his best game as a Chief with a nine-catch, 81-yard receiving game with a TD catch against San Diego earlier this season, was very limited in Thursday's practice. He played sparingly two weeks ago in Oakland, and missed last week's Denver game, with a calf injury.

GAME PLAN: The Chiefs put themselves in position to win in San Diego by containing LaDainian Tomlinson's running (78 yards) and picking Philip Rivers twice. He still threw for 316 yards and two TDs, but his well-oiled passing attack got only 20 points, 10 below the Chargers average at the time. The Chiefs don't pressure quarterbacks, but they must try to contain Rivers by tackling his receivers as soon as they catch the ball. And, then have to limit Tomlinson, who ran for 177 in San Diego's Arrowhead win last year.

Offensively, the Chiefs have had some nice ball-control drives lately, and if they can move the chains, they can keep San Diego's potent passing game off the field.

MATCHUPS TO WATCH: Chargers WRs Chris Chambers, Vincent Jackson and Malcom Floyd vs. Chiefs rookie CBs Brandon Flowers, Brandon Carr and someone in the nickel. Jackson and Floyd pretty much did what they wanted in the first meeting in San Diego. Chambers didn't play then, and now he's back, which is a problem for KC with nickel back Maurice Leggett ailing and possibly out with a shoulder injury.

Chargers TE Antonio Gates vs. Chiefs FS Jarrad Page. Page is a better cover guy than SS Bernard Pollard, and will have to watch for Gates working the deep middle to his advantage.

INJURY IMPACT: Starting C Rudy Niswanger looks very doubtful with a knee injury, though G Wade Smith is an accomplished backup. With starting RG Adrian Jones expected back from a four-week absence with a knee injury, the KC offensive line should be OK. CB Pat Surtain has missed six straight games with a quad injury, and eight total this year. This would be a good time to come back with nickel back Maurice Leggett likely down with a shoulder injury. LB Donnie Edwards (hamstring, knee) has missed the past three games with hamstring and knee problems, and was limited on Thursday. WR Mark Edwards could really help the offense, which has scored only 10 points in each of the two games in which he's been limited or out with a calf injury, if he could return. But he got only a limited workout again Thursday.