Peyton Manning’s football future is being decided by a $28 million bonus, his surgically fused neck and a highly praised college quarterback, ending a record-setting era that produced a Super Bowl title for the Indianapolis Colts.

The club where Manning has played his entire career will release the four-time National Football League Most Valuable Player without paying him the bonus, ESPN and other sources reported Tuesday night, citing unidentified people in the league.

The 35-year-old Manning would become the NFL’s premier free agent, with Nevada oddsmakers saying he’s headed for the Arizona Cardinals.

Manning is coming off neck-fusion surgery that sidelined him for the 2011 season. Colts doctor Robert Watkins said the Sept. 9 operation was successful. Without Manning, the Colts finished 2-14 and gained the NFL’s No. 1 draft pick, which they have said they will use to take Andrew Luck, the 22-year- old Stanford University quarterback rated as the top prospect by ESPN’s Scouts Inc.

Manning, no matter where he winds up, probably will be uninsurable to cover his salary because of his age and injury history, Frank Zuccarello, executive vice president at Exceptional Risk Advisors LLC in Mahwah, N.J. said.

“I can’t imagine anyone even thinking about covering him,” Zuccarello said. “I would think it would be impossible. It would have to come with exclusions for neck and shoulder.”

Zuccarello said if a policy were sold to a team, the premiums could be more than 5 percent of the insured amount, compared with 2 percent for a young, healthy player. With all the exclusions, it wouldn’t be worth it.

Tom Condon, Manning’s agent, didn’t immediately return a telephone message seeking comment on the player’s status. Manning has said he plans to keep playing.

Manning has a 17-percent chance of signing with the Cardinals, according to the Cal Neva Resort’s sports book in Reno, Nev. The Miami Dolphins are second at 14.5 percent, with the Washington Redskins third at 11.5 percent. A winning $100 bet on Arizona returns that stake plus $250.

Indianapolis was 3-13 in 1997 before making Manning the league’s No. 1 draft pick out of the University of Tennessee. The Colts had the same record during Manning’s rookie year before going 13-3 in 1999. Indianapolis won the Super Bowl in February 2007.

MVP Record

Manning, a five-time All-Pro, was named the league’s MVP for the 2003, 2004, 2008 and 2009 campaigns, the most in NFL history.

His 54,828 yards passing, 4,682 completions and 399 touchdowns are third on the NFL career list, trailing leader Brett Favre and Dan Marino in each category. While Favre is also the NFL’s career leader with 336 interceptions and Marino ranks eighth with 252, Manning has just 198, placing him 26th.

Manning had at least three operations on his neck over the last two years. Sports Illustrated, citing unidentified people in the NFL, said last month that the quarterback had a fourth procedure to follow up a May operation for a bulging disk.

Former Redskins General Manager Charley Casserly, now an analyst with CBS Sports, said teams probably will want Manning to sign an incentive-laden contract with a smaller base salary and fewer guarantees. Signing bonuses are paid up front and guaranteed, unlike most base salaries in the NFL.

“You don’t mind paying if the guy plays, but you want to do it on a game-by-game basis with a minimum salary and then either a play-time or weekly roster bonus,” Casserly said.

Andrew Brandt, a former Green Bay Packers executive now an NFL business analyst on ESPN, says teams will want to sign Manning if he is a free agent. The competition might shift the risk back onto Manning’s suitors.

“He’ll have the leverage to get guarantees of millions plus incentives,” Brandt said.

NFL teams aren’t permitted to discuss signing players under contract elsewhere.

Manning signed a five-year contract in July that paid a $20 million signing bonus and a base salary of $6.4 million. He sat out the 2011 NFL season while recovering from the neck injury, ending a streak of 227 consecutive starts.

The Colts have until 4 p.m. Wednesday to exercise the option and keep Manning through 2015. They would then owe him the $28 million bonus plus a $7.4 million salary in 2012, bringing his two-year earnings to $61.8 million, according to Brandt, president of the National Football Post, who analyzed the contract on his website.

The Colts probably would pay Luck $15 million in bonus and salary in the first year. With Manning, that would have meant a commitment to the team’s top two quarterbacks of more than $50 million next season, Brandt said. Luck guided Stanford to an 11- 1 record and passed for 3,170 yards and 35 touchdowns last season.

Brandt said he bought an insurance policy for Favre when the Pro Bowl quarterback signed an agreement with the Packers in March 2001. Favre, then 31 and a three-time MVP, was young and healthy.

Jeffrey Fischgrund, an orthopedic surgeon and editor-in- chief of the Journal of the American Academy of Orthopaedic Surgeons, said the bones above and below a spinal fusion usually compensate for the fused bones, allowing the neck to move normally. He said that 95 percent of people who have the surgery heal successfully and don’t experience further injuries at that site.

“Theoretically, he’s at an increased risk,” Fischgrund, who hasn’t examined Manning, said. “But not so much that you’d expect a catastrophic injury.”

The biggest issue is Manning’s arm strength. Fischgrund said the longer Manning suffers weakness, the longer it will take to make a full recovery. It usually takes a year before people know if they are going to get their full strength back, he said.

“I tell patients, ‘I can’t make you normal, but I can make you better,’” Fischgrund said. “Whether that’s enough for a professional athlete, I can’t say.”