Just about everyone who walked through the doors of the Kansas City Chiefs' practice facility for the start of offseason conditioning Monday wore a wide smile on their face.

The way things have gone the past couple months, they were probably happy to be back to work.

From tampering charges that cost them hefty fines and draft picks this season and next season, to the knee surgery on top pass rusher Justin Houston that could keep him out all season, to early retirements of Mike DeVito and Husain Abdullah, there has been little good news emanating from Arrowhead Drive.

Even the signing of veteran pass rusher Tamba Hali carried a cloudy lining: The Chiefs squandered some much-needed salary-cap space by failing to reach the agreement by a deadline contained in his previous deal.

So yes, Derrick Johnson and Co. were happy to be lifting weights and worrying about football again.

"The team is always different when you come back, regardless of what year it is," said Johnson, who signed a three-year deal this offseason to stick with the Chiefs. "First day of OTAs, first day of offseason training, it's good to get back with the guys that have been off a few months."

Catch up on each other's rehab, too.

Start with star running back Jamaal Charles, who tore his right ACL last season. The former All-Pro watched the Chiefs win their first playoff game in more than two decades from the training room, but has started to run and is eying the start of training camp for getting back on the field.

"I'm in the stage of running right now, just basically trying to get my leg caught up to my left leg and get that strength back in it," he said. "I'm very fortunate to walk and now run."

Then there's cornerback Phillip Gaines, who tore the ACL in his left knee but it also back to running. His return could prove crucial to a secondary that lost physical cornerback Sean Smith to AFC West-rival Oakland.

"It's getting there," he said. "The training staff is doing an unbelievable job with me. I fought through a tough time — any time you're away from football is hard. They kept with me."

Dustin Colquitt also had knee surgery, though the punter's procedure was more to "clean out" the crucial joint than repair anything. Colquitt said he's been working out for about two months, including some running and kicking, and "'m glad everybody is back. The building is pretty empty in the offseason."

Hali, whose three-year deal came after the Chiefs learned of Houston's injury, also had minor knee surgery after dealing with swelling much of last season. The longtime Chiefs pass rusher plans to take a similar approach to this season, which means resting much of the week to be ready for game day.

Defensive tackle Dontari Poe said his back feels better after having surgery last summer, and acknowledged Monday that he may not have been "100 percent" at any point during the season. Several other players also reported in good health, including left tackle Eric Fisher, who has dealt with several injuries early in his career.

As for the tampering charges, the Chiefs had their appeal of penalties rejected late Monday, which means they lose their third-round pick this year and sixth-rounder next year. Wide receiver Jeremy Maclin, whose free agency was at the center of the case, declined to discuss it in detail.

"It's been a weird situation," Maclin said, "but I'm happy with where I'm at. I wouldn't change it for the world and everything else will take care of itself."