A person familiar with Manning's location says the free-agent quarterback flew to Arizona on Saturday night for meetings with the Cardinals.
The Arizona Republic was the first to report that the four-time MVP had arrived.
The person spoke to The Associated Press on condition of anonymity because of the sensitivity of the situation.
The former Indianapolis Colts star met with the Denver Broncos on Friday night at the team's headquarters He is expected to meet with Cardinals coaches and team officials on Sunday. After Arizona, Manning reportedly is going to Florida to meet with the Miami Dolphins.
The Manning stakeout in Arizona began earlier Saturday, but there was no sign of him.
The Cardinals' facility was a bee hive of activity as the setting for Kurt Warner's annual "Ultimate Football Experience," a fundraiser for his First Things First foundation that features current and past football stars. Among them was Cardinals star wide receiver Larry Fitzgerald, who said he knew nothing of any contact the team may have made with Manning.
"I haven't heard anything," he said. "I'd like to feel like if he was going to be here I would probably hear something from somebody."
The presence of Fitzgerald, one of the best receivers in the game, is considered a major reason why Manning would consider the Cardinals, who won seven of nine after a 1-6 start to wind up 8-8 last season.
The team already has invested millions in quarterback Kevin Kolb and is scheduled to pay him $7 million if he is on the roster Thursday. The Cardinals, though, had more success with second-year quarterback John Skelton starting than with Kolb, who missed much of the season with turf toe and a concussion.
Fitzgerald, the Cardinals' career leading receiver, said he understood why Arizona would be interested in Manning.
"He's a four-time MVP. He's a Super Bowl champion," he said. "He's arguably the best quarterback to ever play football. He's a free agent. If he's healthy, I know he's somebody that can help any team that he goes to. I understand the interest. It makes sense."
Fitzgerald said he wasn't surprised Arizona is in the mix.
"After last year, Michael (team president Michael Bidwill) said he was going to continue staying aggressive," Fitzgerald said, "and he's going to do everything he can to make sure we're going to be able to compete for an NFC West championship every single year. He hasn't done anything to this point to make us believe anything different."
Besides Fitzgerald, the Cardinals can offer a state-of-the-art stadium with a retractable roof and natural grass field that slides out into the sunshine when not being used. Then there is the weather - sunshine with the temperature in the high 70s on Saturday.
The Cardinals have a strong young defense but Manning might be concerned with an inconsistent offensive line that could lose left tackle Levi Brown, unless he restructures his contract. Other than Fitzgerald, the receivers are young.
Warner, who led St. Louis and Arizona to the Super Bowl, said he's a bit surprised the Cardinals are in the running, mainly because of the investment they made in Kolb, who was acquired from the Philadelphia Eagles for cornerback Dominique Rodgers-Cromartie and a second-round draft pick.
"But I think that speaks volumes about where the organization is at right now," Warner said, "how far they've come, in saying `Hey, we want to win. No offense to the guys that we have, but if we feel like we can upgrade a position and we can be better, we're going to make a play at that.' You have to commend an organization for doing that."
Warner, now an analyst for the NFL Network, does not see the Cardinals as favorites in the Manning sweepstakes.
"I think Miami still has the upper hand," he said. "I don't necessarily know why I think that. I just think since day one they've made it known `We want him to be our guy and we'll do whatever we have to do to get him.' I think if you're a guy in that situation, at that stage of your career, that's what you want to hear. You want to go somewhere where they're saying `We're going to roll out the red carpet. Whatever you need we're willing to make those moves, bring a receiver with you, sign you to whatever kind of deal you want.'"
Manning became one of the most sought after free agents ever when he was released by the Colts, part of a massive roster makeover for the team that had the worst record in the NFL last season, when its star quarterback was injured. The Colts dumped Manning and are expected to take Andrew Luck with the first pick in the draft.
After an emotional farewell in Indianapolis, Manning has moved swiftly to find a new home. After a series of neck surgeries, he has reported good progress in regenerating the nerves and regaining his masterful passing ability.
He got a high-profile welcome in Denver.
According to The Denver Post, the Broncos sent a plane to pick up Manning in South Florida, where he has a condo. He had traveled there after an emotional news conference in Indianapolis on Wednesday, when he said goodbye to the team that drafted him No. 1 overall in 1998 and he led to the 2007 Super Bowl championship.
The plane then stopped in Stillwater, Okla., where Broncos vice president of football operations and Hall of Fame quarterback John Elway, coach John Fox and general manager Brian Xanders were watching Oklahoma State's pro day. The Broncos management met up with Manning, and everyone flew back to Denver.
ESPNews carried live coverage of the flight arriving at an airport in Denver, then also followed Manning's car ride to Broncos headquarters. And while Manning met with Elway & Co. inside the building, a blue helicopter hovered overhead.
The Kansas City Chiefs also have expressed interest, but there was no known scheduled visit there.
"There's excitement around our league, and excitement about what we're going to see from Peyton Manning, where he's going to go, if he's going to make a team an instant competitor for a championship," Warner said. "All those things are great for our league. I'm excited to see, just like everyone else, how this plays out."
(Copyright 2012 The Associated Press. All RIghts Reserved)