Kansas City, Mo. ? Eric Warfield finally is back as a starting cornerback, so maybe Kansas City’s supposedly improved defense will begin to play like it.

Their 4-2 record after six games would suggest an upgrade from last year when they were 2-4. And the run defense obviously is improved, with an average yield of only 95.5 yards per game that ranks in the top 10 in the league.

While finishing 7-9 last year, they were 31st in total defense and dead last in pass defense. Going into Sunday’s game at San Diego, they’re near the bottom in total defense, giving up almost 360 yards per game.

And their pass defense, statistically at least, still is poor. With Warfield playing only in last week’s 30-20 victory over Miami, the Chiefs have given up 263.7 yards passing every game – which is not exactly what they had hoped for after bringing in safety Sammy Knight and cornerback Patrick Surtain.

Nevertheless, coach Dick Vermeil remains upbeat.

“I believe they are (getting better),” he said Tuesday. “Of course, I always see things as getting better. Sometimes I’m a little blind, but I just feel we are getting better.”

Warfield sat out the first four games under NFL suspension for DUI and then was left inactive for the fifth game of the year, possibly because he was still in the coaches’ doghouse for an uninspired training camp. But the veteran cornerback made his first start at Miami and will get another start on Sunday at San Diego.

He seems to be back to his old spot, and that will help a defense still trying to adjust to new wrinkles and different people.

“It’s different,” Warfield said. “You can go out and do all sorts of conditioning workouts. I thought I was 100 percent ready to get in there and give it my best. And even though I did go play a pretty decent game, when I finally got onto that field and the whistle blew, I realized there were a few little things I needed to work on to get back to where I used to be.”

He discovered, as some veterans had warned, that the only way to get into top football shape was to play football.

“You have to be in a game,” Warfield said. “You can watch all the film and do all the conditioning you want to do. But if you’re not in the game getting the feel of it, you’re just not going to have it.”

The 2004 defense gave up an average of 132 yards rushing, almost 40 yards more than the 2005 unit has allowed the first six games.

Improved speed at linebacker has made an obvious difference there.

“Once we started putting the pads on in training camp you had the idea we were going to be pretty successful in that aspect,” defensive end Eric Hicks said. “We need to clean some things up, but we’re working hard on that. Everybody knows it’s a one-gap defense and everybody is playing to the best of their ability.”

One blow to the defense came in the first game when defensive tackle Ryan Sims went out because of a foot injury, further making it more difficult to get the wrinkles out of what defensive coordinator Gunther Cunningham calls the new culture of defense.

“The culture change that he talks about is not complete yet,” Hicks said. “But we’re getting there. We’re battling our tails off every day. When we’re firing on all cylinders, it’s going to be hard to stop us.

“There’s a tremendous amount of confidence out there. Everybody’s fired up. Everybody’s excited when it’s our turn to go back on the field.”