As the Kansas City Chiefs opened camp Friday on lush, green practice fields dotting a countryside yellowed and browned by drought, most eyes were on just three guys.

How are the knees of Jamaal Charles, Eric Berry and Tony Moeaki holding up?

Fingers are crossed.

Taken together, the knee injuries that took out the Pro Bowl running back, Pro Bowl safety and promising tight end before the 2011 season probably had more to do with last year’s dismal campaign than any other factor. Had Charles been given a chance to duplicate his 1,467-yard season of 2010, Todd Haley might still be the coach rather than Pittsburgh’s offensive coordinator.

Most of the defense had been designed around Berry after he played well enough as a rookie to go to the Pro Bowl. Had he spent 2011 in the secondary rather than rehab, Kansas City fans may have enjoyed a second straight trip to the playoffs.

Instead, the wounded Chiefs limped home 7-9, runner-up in the mediocre AFC West to 8-8 champion Denver. Haley was fired and Romeo Crennel was promoted from defensive coordinator.

Their head coach will be keeping a keener eye than anyone else on how well these vital players are moving and cutting, stopping and starting on their surgically repaired knees.

So far, so good.

“They all passed the physical and we will be working with all of them in practice,” Crennel said. “We might have to manage them a little bit if they get a little irritated in their joint they had the surgery on. But they should be good to go. they’re excited and they’re ready and they want to go.”

Crennel said he’s seen nothing in the three to cause worry. At least, not yet.

“What’s going to happen, that joint hasn’t been stressed the way it’s going to be stressed in pads and out there on the football field, and sudden cuts and things,” said Crennel. “Most of the work they’ve been doing in the offseason, it’s all planned. It’s straight-line. They know when they’re going to make the cut, they know when they have to turn. They can go straight ahead. But on the football field, it has to be a reaction.”

As expected, wide receiver Dwayne Bowe, Kansas City’s leader in receptions and receiving yards the past three years, was not on the field Friday. Bowe, a Pro Bowler in 2010, was given the franchise tag when he refused to sign the Chiefs’ tender.

If he eventually comes in and plays this year, as the Chiefs expect, he will get about $9.5 million.

“The only thing I can tell you is he’s not here,” Crennel said. “I’m only working with the guys who are here, so I know nothing about the situation. I have not spoken with him or anything like that.”

The Chiefs do not expect Bowe to sit out. But as long as he’s out, it is an opportunity for second-year wide receiver Jonathan Baldwin to get his career started. Last year’s first-round pick, Baldwin missed much of the first half of the season after injuring his hand in a fight with teammate Thomas Jones.

“Last year he had an injury and that slowed him down. but he kind of feels like he might be the guy and he sees the opportunity, and he worked hard this offseason,” Crennel said. “His weight is down. He’s in great shape. He’s got a good attitude. I anticipate he will have a good year going forward.”

Starting left tackle Brandon Albert and reserve defensive back Jacque Reeves were absent for what Crennel described as “family issues,” and both were expected to be in camp soon.