The calendar, however, doesn't stop for anyone.
Manning turned 37 since the last time he threw a meaningful pass -- the interception that led to Baltimore's winning score in its double-overtime victory in the playoffs -- and that so-called window to win a championship will close soon.
Even that sort of forward thinking, however, doesn't jibe with Manning -- whose contract is guaranteed through 2014, but who takes things one practice, one game, one season at a time.
"I don't have a set number," Manning said Thursday, after the first practice of training camp, when asked how many more years he can play. "I'm all in on 2013."
All the Broncos are.
This is a team built to win right now, based largely on the fact that John Elway took a chance on the prized quarterback last offseason and has spent all his time since spending big to assemble a team full of veterans to surround him.
"Our goals are set high," coach John Fox said. "From our owner on down, he wants to win a championship and he wants to win them back-to-back. That has been done here in this organization, so it's not just talk and that's everybody in this building's goal."
To take the next step, Elway added Wes Welker to Manning's already strong receiving corps -- part of a busy offseason during which he spent $125 million, counting the re-signing of left tackle Ryan Clady.
"I don't know if you saw him out there today," Manning joked about Welker, who caught his first training camp passes in front of about 3,000 fans who came out for opening day.
Manning has always insisted it takes years, not weeks or months, to build strong connections with new receivers. He doesn't have that kind of time, of course, so he's doing the best he can. Now nearly 18 months removed from the last in a series of surgeries on his neck, Manning said he feels stronger, even better than he did last year, when he threw for 4,659 yards and 37 touchdowns, both the second-highest total of his 16-year career.
As for a certain throw or feeling he's experienced on the field this offseason that signals to him he's all the way back -- well, it's nothing that concrete.
"I can't really think of a specific throw," Manning said. "I think when you know your teammates better, when you have your timing better with your teammates, that certainly always has allowed for more precise throws, more confident throws."
Like the rest of the Broncos, Manning has been itching to get back since last season's playoff loss to Baltimore. The Broncos were 13-3, on an 11-game winning streak, top-seeded in the AFC and top pick to go to the Super Bowl.
Elway, drawing comparisons to Denver's flameout in 1996 that was followed by Super Bowl titles in 1997 and 1998, is trying to make sure there's no sense of complacency this year. At minicamp in April, Manning said he could tell Elway was trying to create an "uncomfortable atmosphere" to keep everyone motivated.
"We still kind of have a scar from losing that playoff game and I think players need to kind of be reminded of that daily," Manning said on the first day of training camp.
But there have been signs that the Broncos aren't totally focused.
Over the past month, Manning has sat back and watched the bad news unfold for Denver. First, two executives were suspended after being charged with drunken driving. Then, training camp began with All-Pro linebacker Von Miller appealing a four-game suspension for violating the league's substance-abuse policy.
Times like these, Manning said, are when you find out who's with you and who isn't.
"It's easy when you are rolling along, an 11-game winning streak, everything is good," Manning said. "You have some adversity come your way. How do you respond? How do you handle it? I think the organization has responded. They made their statements and we'll support those that are going through some adversity. At the same time, we're going forward trying to win."
Even with their problems, the Broncos are expected to win.
They're the odds-on favorite to win the Super Bowl, in fact.
And though Manning is the king of preaching the one-practice, one-game-at-a-time mantra, he isn't shying away from expectations -- at least not on the first day of training camp.
"There are outside expectations and there are internal expectations," Manning said. "And like Coach Fox said last night, I guess it's a good thing that the outside world has high expectations for us as opposed to expecting nothing from us."