RALEIGH, N.C. (AP) -- Peyton Manning won't be a Dolphin or a Cardinal. But he could still join the Titans, the Broncos or even -- get ready for this -- the 49ers.
The race to sign the NFL's only four-time MVP and the most prized free agent of the offseason heated up Friday as Denver Broncos executive John Elway and coach John Fox watched the star quarterback throw at Duke and San Francisco was revealed as a stealth suitor.
A person familiar with the situation said that Manning worked out for 49ers' coach Jim Harbaugh on Tuesday night at Duke. ESPN first reported on the session.
Manning also threw the ball at Duke's athletic fields Friday afternoon for the Broncos. He was seen leaving the Blue Devils' indoor practice facility wearing blue shorts, a gray t-shirt and no helmet heading to the outdoor practice field followed by Elway and Fox.
Manning came off the field about 4 p.m., and the Broncos contingent left about the same time.
"We enjoyed visiting with Peyton today in N.C.," Elway tweeted later. "He threw the ball great and looked very comfortable out there."
Another person confirmed to the AP that Manning phoned the Miami Dolphins on Thursday to advise them he'll sign elsewhere. The team has now turned its attention to free agent quarterback Matt Flynn.
The people who spoke to the AP did so on condition of anonymity because Manning's workouts have remained private and all the teams involved have refused to comment about their free agency negotiations.
The record-setting quarterback has been rehabilitating in North Carolina after a series of neck surgeries. Duke coach and longtime Manning friend David Cutcliffe told The Tennessean that Manning has made good progress throwing the football following the operations, which forced him to miss the entire 2011 season.
Manning's uncertain health led the Indianapolis Colts to balk at paying a $28 million roster bonus to the 35-year-old quarterback. The colts released Manning on March 7, which in turn triggered a flurry of meetings and visits.
The 49ers had been working to re-sign quarterback Alex Smith, the No. 1 overall draft pick in 2005 who made a comeback in 2011 under first-year coach and former NFL QB Harbaugh, and Smith has acknowledged he was happy with the three-year offer.
Smith and Manning both are represented by Tom Condon and CAA Sports.
"Alex is trying to figure out what he wants to do," 49ers CEO Jed York said earlier this week. "There have been good conversations back and forth."
The NFC West champion 49ers on Monday signed wide receiver Randy Moss after he spent a year out of football, hoping he will be the dynamic wideout and deep threat he once was and will open up the field.
An email to Smith, multiple phone messages to his agency and to his father were not returned.
The 27-year-old Smith threw for 3,150 yards and 17 touchdowns with only five interceptions as San Francisco went 13-3 and made the NFC title game last season after an eight-year playoff drought.
Neither running back Frank Gore nor tight end Vernon Davis had been told by the 49ers they were pursuing Manning. Both are big fans of Smith. Asked if Smith is still the man, Gore said, "I think he is."
Manning's whirlwind free agency tour officially kicked off soon after he bid farewell to the Colts in an emotional press conference.
The Broncos had the first crack at wooing him, rolling out the red carpet for his visit. Team officials flew him in and he spent the spent the day chatting with Elway, the Hall of Fame QB turned team executive. Manning also was escorted around the team's building by Fox and general manager Brian Xanders as he listened to their sales pitch.
After that, Manning journeyed to nearby Castle Rock, Colo., and spent the evening with good friend Brandon Stokley, who played catch with Manning the next morning and spoke highly of his former teammate in an interview on a local radio show.
Manning's next stop was Arizona, where he met with the Cardinals for nearly 6½ hours. But the Cardinals also seemed to be out of the running on Friday, opting to pay quarterback Kevin Kolb a $7 million roster bonus he is due on Saturday.
Tennessee, however, remains in the picture. Manning has a big fan in 89-year-old Titans owner Bud Adams, and the former Tennessee Volunteer spent nearly eight hours this week with team executives on a plane and at the club's headquarters.
The NFL Network reported that Manning was expected to work out for the Titans, but there was no immediate confirmation from the team or word on when that would happen.
AP Sports Writers Steve Wine in Miami and Pat Graham in Denver and Janie McCauley in San Francisco contributed to this report.