INDIANAPOLIS — Indianapolis Colts quarterback Peyton Manning is entering his ninth season and figures he has hit the halfway mark on an NFL career that has seen him enjoy record-breaking moments and endure gut-wrenching setbacks.

The former University of Tennessee star turned 30 in March, making him one of the older players on the roster. That hasn’t gone unnoticed by a few of his younger teammates.

In the days leading up to the Colts’ mandatory three-day minicamp, Manning occasionally would pass a rookie in the locker room.

"A couple of them called me ‘sir’ or ‘Mr. Manning,’ which makes me feel really, really old,’’ Manning said. "I don’t think I deserve that.’’

He laughed softly, but the fact remains the face of the Colts isn’t getting any younger. Of the NFL’s 32 projected starting quarterbacks for the upcoming season, only 11 are older than Manning.

Now that he has joined the thirtysomething crowd, it’s Manning’s desire to stick around for another eight seasons. That would take him through the 2013 season and culminate in a 16-year career.

That’s the number — 16 — that always has popped into Manning’s head whenever anyone has asked how long he intends to play. His father, Archie, played for 15 seasons. Denver’s John Elway played for 16 seasons and Miami’s Dan Marino for 17.

"I’ve just always picked 16 years for myself,’’ Manning said, "so I’ve just finished the halfway point. I still feel like I’m in a young body. Certainly I’ve been fortunate healthwise and I’ve had outstanding protection my entire career. I still feel very healthy.’’

To ensure he remains that way, quarterbacks coach Jim Caldwell altered Manning’s offseason workout regimen. Manning wasn’t allowed to throw a football in practice until May 1.

"That’s the latest I’ve ever started,’’ Manning said. "It’s very much like a baseball pitcher. I’ve tried to watch my arm and monitor my throws.’’

Caldwell uses a counter on the practice field to make certain Manning doesn’t exceed his "pitch count.’’

"My arm feels live and rested,’’ Manning said. "The key is to maintain that throughout the season.’’

On a broader scale, the key, individually and collectively, is to find a way to carry over successes from the regular season to the postseason.

Since 1999, the Colts are the NFL’s winningest team in the regular season with a 77-35 record. With a 14-2 record last season they became just the seventh team in NFL history to win at least 12 games in three consecutive seasons. Only the 1992-95 Cowboys have strung together four consecutive seasons with at least 12 wins.

But for all of their regular-season accomplishments, the Manning-led Colts are 3-6 in the postseason and have yet to reach the Super Bowl. Their most recent failure might have been the most difficult to digest — a 21-18 loss to Pittsburgh in the RCA Dome in an AFC divisional playoff game.

"You can find a lot of different ways to summarize the game,’’ Manning said, "but it comes down to the fact Pittsburgh played better than us. It’s difficult to swallow, but all you can do is try to learn from it.’’

This has been an offseason of change for the Colts, with running back Edgerrin James, linebacker David Thornton, defensive tackle Larry Tripplett and place-kicker Mike Vanderjagt departing via free agency. Even so, the spotlight undoubtedly will focus brightest on Manning as the team moves ahead.

However, coach Tony Dungy isn’t expecting anything extraordinary from his quarterback. Just more of the same.

"His next step is to continue to play like he has and continue to be productive and continue to do the things we need for him to do,’’ Dungy said.

Since Dungy’s arrival in 2002, Manning has taken his game to another level. During the past four seasons, he’s compiled a 102.4 quarterback rating by averaging 4,193 yards and completing 67 percent of his passes for 133 touchdowns with 49 interceptions.

Forget the individual numbers, insisted Manning. It’s all about another title shot.

"We’ve had some opportunities and put ourselves in position,’’ he said. "When you’re in the middle of your career like I feel I am, all you can do is learn from the previous season and try to be better the next year and find a way to help your team win a championship.’’