Kansas City, Mo. ? One cornerback is nursing an injured knee, and the other is limping on a painfully bruised hip.

The new safety is taking lots of heat for missing a crucial tackle in a loss to San Diego last week. These are not the best of times for a Kansas City secondary that was supposed to be improved this season.

And, in fact, it is. The defensively challenged Chiefs last year finished 32nd, dead last, in pass defense. Now almost halfway through the year, following last week’s 28-20 setback in San Diego where tight end Antonio Gates caught 10 passes for 145 yards and three touchdowns, they’re No. 31.

Even coach Dick Vermeil reluctantly admits where he might start if he were putting together an offensive game plan against the Chiefs.

“I’d throw the ball,” he said.

One area of improvement has been the run defense. Opponents are running for only 93.7 yards per game, putting Kansas City in the top 10.

Vermeil also insists the talent is there to improve the pass defense.

“Sometimes it’s the players you play against, and the situations,” Vermeil said Tuesday. “For example, the big tight end (Gates) ate us up pretty good with 10 receptions. They beat us for touchdowns, throw a quick one and we don’t wrap up real well on the tackle and the big guy wins the battle. Whatever it is, it’s not good enough.”

San Diego tight end Antonio Gates, right, runs past Kansas CIty's Sammy Knight after catching a fourth-quarter pass he turned into a touchdown. Gates helped the Chargers beat K.C., 28-20, Sunday in San Diego, exposing the Chiefs' porous pass defense.

Cornerback Patrick Surtain, one of two big-name newcomers brought in to boost the secondary, generally has played well. But he went out Sunday because of an injured knee and his status is uncertain.

One reason for the slow start also may be that starting cornerback Eric Warfield was unavailable the first five games. He was suspended the first four games, and then did not make the active list on the fifth.

He started against the Chargers, but was slowed because of a hip pointer. In addition, backup safety Jerome Woods may be listed as doubtful with a hamstring injury.

“My biggest concern would be Patrick Surtain starting at corner,” Vermeil said.

There apparently is no damage to the knee.

“It’s a knee he’s had worked on before,” Vermeil said. “The doctor said the knee is stronger and tighter today than it was when we signed him originally. But it doesn’t mean he’s not sore.”

The man who beat out Woods this year, Sammy Knight, has had his good moments and his bad since being acquired over the offseason. One of his worst came against Gates when the tight end took a short pass, broke Knight’s tackle as though his jersey were greased, and dashed into the end zone for his third TD.

“Sammy Knight in the ballgame made six tackles. He had a missed tackle and three passes defended. We would have liked him to make that tackle on their great tight end at that time. Then it would have been a pretty good football game for him,” Vermeil said.

Earlier this season, Knight was given a game ball after knocking away the potential game-tying touchdown pass in the end zone to seal a victory over Washington.

“Overall, I think he’s playing well for us,” Vermeil said. “The trouble is, when the safety makes a tackle in a blitz situation or misses a tackle in a blitz situation, it’s like a field goal kicker missing a field goal.

“That’s one play that hurt us, no question. And he’s the kind of player who normally makes that kind of play.”

One other injury of concern is to running back Priest Holmes, who sustained what was described as minor head trauma in San Diego and did not return.

“We’re going to get a little more evaluation on him,” Vermeil said.