INDIANAPOLIS -- Peyton Manning made it out to practice Monday.
He's still nowhere close to throwing yet.
The four-time MVP was in good spirits when he made his first public appearance on the field since having neck surgery Sept. 8.
"Save a copy for me for my scrapbook," Manning joked as he walked past the television cameras filming his arrival.
Those around Manning are not elaborating about his medical recovery.
Fox Sports, citing an unnamed source, reported Sunday that Manning traveled to Europe for stem-cell treatment before his latest surgery. The procedure has not yet been approved for use in the United States.
Colts vice chairman Bill Polian and Tom Condon, Manning's agent, both declined to comment about the report following Sunday's 27-19 loss to Cleveland. On Monday, Manning's surgeons followed suit and Caldwell reiterated that the team would not provide any additional details about Manning's progress.
"Just in terms of how we've handled things around here, we have not discussed anything of that nature in terms of medical situations or whatever it may be," Caldwell said. "I think, also, in (the Sept. 8) release, we stated that we're not going to discuss anything further, and that's where I'm going to end it."
Dr. Gowriharan Thaiyananthan, co-medical director of the Chapman Neurosurgical and Spine Institute in Orange, Calif., said it's possible stem-cell treatment could speed up Manning's recovery.
But it's still unlikely, Thaiyananthan said, that the Colts will get Manning back sooner than the current timetable.
Manning is expected to miss at least two months after having an anterior fusion to treat a nerve injury that was causing weakness in his triceps. The procedure normally involves making an incision in the front of the neck, removing soft disk tissue between the vertebrae and fusing the bones together with a graft. The goal is to ease pain or address a disk problem.
Some doctors have said the recovery can take four months or longer, which could keep Manning out all season.
"He still has to recover from a cervical fusion, so I think that will be several months," Thaiyananthan said. "I think the hope is that he can get back to playing sports."
The stem-cell treatment does not use embryonic stem cells, which have caused so much consternation in the U.S., but rather cells from Manning's own body. Doctors harvest the cells, expand them and then put them into the body.
It's a procedure Thaiyananthan believes athletes may use more frequently in the future so they can avoid surgery. He's not alone.
"The stem cells very quickly affect the inflammation and then they're like a factory where they will regenerate right at the site," said Kevin Dunworth, founder and CEO of SpineSmith in Austin, Texas.
Manning had a prior surgery May 23, but that did not fix the problem.
The Colts are hoping this latest procedure will.
"He's convalescing from the surgery and that will take a little while yet, and then at some point, the doctors will bring him back and assess his situation," Polian said on his weekly Monday night radio show. "We're not sure when that will take place. He's up and around, I can tell you that. But it is surgery, and there is a period of time where it takes its toll on you, and that's where he's at right now."
Teammates were happy to have Manning back on the field -- even if it was only as a spectator.
When five-time Pro Bowl receiver Reggie Wayne walked past reporters and saw Manning, he blurted out: "(He's) walking it off."
The injury ended Manning's streak of 227 consecutive starts, including the playoffs, and without him, the Colts have not been the same.
They're off to their first 0-2 start since 1998, Manning's rookie season, and have scored only two touchdowns in eight quarters. Panicked fans are calling for changes, even replacing Kerry Collins who has started the first two games.
The Colts, however, are more worried about fixing the mistakes than making personnel changes.
"For the foreseeable future, it's not going to be the high-efficiency offense that we've been used to," Polian told listeners. "Kerry can't do that, nobody can. You could probably bring back Johnny U. (Unitas) and you wouldn't have that."