ENGLEWOOD, Colo. (AP) -- Wes Welker celebrated Labor Day by practicing for the first time since sustaining a concussion on Aug. 23.
Welker donned his up-sized helmet and ran short routes during the 20-minute viewing period open to the media at the start of practice, He added a few minutes of extra work with rookie Cody Latimer afterward.
With injury reports not required until Wednesday, coach John Fox was coy when asked how much work Welker did in between.
''He's still in the (concussion) protocol. He's still exercising. I feel good about his progress. We'll keep you posted,'' Fox said.
Welker declined to talk with reporters on his way inside team headquarters after practice, saying he had to rush to a team function.
His concussion in a preseason game against the Houston Texans was his third since Nov. 17.
In a sign that his latest head injury wasn't as serious as last year's pair of concussions in a three-week span, Welker ran a few routes in a pregame workout for starters who didn't play in the exhibition finale at Dallas on Thursday night.
Welker's return to action leaves the Broncos with just two key players sidelined: linebacker Danny Trevathan (leg) and kicker Matt Prater (suspension). Key backups Ronnie Hillman and Kayvon Webster were limited in the early portion of practice four days after falling ill during the Broncos' exhibition finale at Dallas.
Welker's return to the lineup would allow the Broncos to keep burner Emmanuel Sanders on the outside and available to stretch the field by going deep along with Demaryius Thomas.
Welker caught 73 passes for 778 yards and a career-high 10 TDs last season despite missing most of the final month. He returned for the playoffs and grabbed 18 passes for 160 yards and a touchdown.
His latest head injury came when he tried to duck following a catch over the middle and absorbed a helmet hit by D.J. Swearinger that sent his head recoiling off the ground.
That drew a 15-yard penalty for Swearinger and the wrath of Manning. The quarterback raced up to say some choice words to the swaggering safety after throwing a long TD pass to Sanders on the next play.
The five-time MVP was whistled for the first taunting penalty of his career and was fined $8,268, money Manning called well spent. The NFL, meanwhile, deemed Swearinger's hit legal.
Manning's feistiness further galvanized the Broncos, who are trying to become an edgier team in their quest to get back to the Super Bowl and win it this time.
Several starters who skipped the Super Bowl while rehabbing from injuries are back, including Manning's blindside protector, Ryan Clady, and defenders Von Miller, Chris Harris Jr., Rahim Moore, Derek Wolfe, Quinton Carter and Quanterus Smith.
At the top of GM John Elway's to-do list following Denver's dud against Seattle was to toughen up his defense - yes, sort of like the Seahawks. So, he added DeMarcus Ware, T.J. Ward and Aqib Talib in free agency and Bradley Roby in the draft.
Only three defenders who started in the Super Bowl are still starters seven months later: tackles Terrance Knighton and Sylvester Williams, and linebacker Nate Irving.
Among Elway's toughest cuts last weekend were defensive tackle Kevin Vickerson and safety Duke Ihenacho, who was snatched up by Washington.
''It's a situation you want to be in, having to make a lot of tough decisions,'' Elway said. ''This is by far the deepest team since I've been here and the toughest decisions we've had since I've been here.''
This should also be the toughest team he's had in Denver. And not just on defense. The offense has a new edge to it, too, as evidenced by Manning's feistiness.
''That's how we are,'' Talib said. ''He was defending his teammate. That's what he's about - all of us.''
NOTES: Five Broncos were voted captains by their peers Monday: Manning, Thomas, Ware, Knighton and David Bruton. ... The Broncos filled out their practice squad by signing DE Zach Thompson, a rookie from Wake Forest who was in training camp with the Jets.
AP NFL website: www.pro32.ap.org and www.twitter.com/AP-NFL