Kansas City, Mo. ? The Chiefs ruled out Justin Houston for Sunday’s game in San Diego because of swelling in his surgically repaired left knee, throwing into question the four-time Pro Bowl pass rusher’s status for the playoffs.

Kansas City also activated linebacker Justin March-Lillard from injured reserve and waived defensive lineman David King on Friday. March-Lillard has been practicing for a couple of weeks after breaking his hand earlier this season, but coach Andy Reid said he is unlikely to play this week.

Running back Spencer Ware is listed as questionable for the Chargers with bruised ribs.

Houston was also inactive for last week’s win over Denver, which clinched Kansas City’s postseason spot. But the Chiefs still can win the AFC West, earn a first-round bye and play a home playoff game by beating the Chargers on Sunday if division-leading Oakland also loses to the Broncos.

Now, the Chiefs could be without several important players for an important matchup.

“Listen, I thought the guys had a good week,” Reid said Friday. “They came out in this nice windy weather that we had, and I thought prepared well. They understand what San Diego is all about and how explosive they are offensively. They have a young defense that is flying around.

“We have a lot of respect for them as coaches and players.”

Houston had surgery to repair the ACL in his knee in February, after the team struggled to determine the extent of the injury late last season. He didn’t make his season debut until Nov. 20 against Tampa Bay and had three sacks the following week in Denver, with a fourth sack the next week in Atlanta.

But the standout linebacker was held in check by Oakland and virtually disappeared a couple weeks ago against Tennessee, the first obvious sign that Houston’s knee was bothering him.

“I think we just take it day-by-day and we just see,” Reid said earlier this week. “I know how these things work. I’ve been there and I know it. I think it’s just a matter of calming it down a bit. I think if we just take it day-by-day we’ll be good to go.”

The Chiefs elected to reinstate March-Lillard from injured reserve rather than running back Jamaal Charles for two reasons: He appears to be closer to game-ready and fills a bigger need after the loss of middle linebacker Derrick Johnson to a ruptured Achilles tendon.

But asked if he’d play against the Chargers, Reid replied: “I’d probably lean away from that one.”

Ware was hurt late in last week’s win over the Broncos, and Charcandrick West took most of the carries down the stretch. Ware had an MRI exam on his bruised ribs early in the week and was limited every day in practice, so even if Ware is available his role could be curtailed Sunday.

Also questionable was cornerback Phillip Gaines, who’s been dealing with a bothersome knee, while wide receiver Chris Conley was a full participant in Friday’s practice after having a sore ankle.