TERRE HAUTE, Ind. (AP) — Peyton Manning was back on the practice field Monday. His longtime sidekick, Marvin Harrison, was nowhere near Colts’ camp.

Or the NFL.

For the first time in Manning’s 12 NFL seasons, he is starting camp without his right-hand man, a salary-cap casualty.

“It certainly is different, and it is certainly an adjustment,” the three-time league MVP said. “But it’s like coach (Jim) Caldwell said last night, you have to go with who’s here.”

The Colts do have a succession plan in place.

Three-time Pro Bowler Reggie Wayne, who has been lining up on the left side, officially replaces Harrison in the Colts’ receiving hierarchy. Anthony Gonzalez, a first-round pick in 2007, is expected to take over as the No. 2 receiver in Harrison’s old spot on the right side. The battle for No. 3 will likely come down to Pierre Garcon, Roy Hall and rookie Austin Collie, a fourth-round draft pick.

Wayne has been preparing for this transition for years and has steadily earned Manning’s confidence. In 2007, Wayne caught 104 passes for 1,510 yards, both career-highs, when Harrison missed most of the season with a knee injury.

Gonzalez, now in his third season, is ready to take the next step after fighting through injuries as a rookie and emerging as a consistent contributor in Year 2.

Yes, Manning likes the talent he has on the field. It’s just odd not seeing No. 88 at practice.

“I think it will probably sink in even more, probably the most when we play that first preseason game against Minnesota, because that’s really all that I’ve ever known,” Manning said.

For more than a decade the two were inseparable.

They combined for more completions, more yardage and more touchdowns than any passing duo in league history. When they broke the record for touchdowns by a quarterback-receiver tandem, Manning even suggested they cut the ball in half.

But Manning still recounts one August day in 1998, shortly after the two started working together as the start of their record-setting partnership. They were in Seattle, when offensive coordinator Tom Moore instructed Manning to throw his first NFL pass to Harrison. The result: 48-yard touchdown.

“I was thinking, ‘Man, this NFL is pretty easy. All you do is throw the ball to Marvin Harrison and he catches touchdowns,'” Manning said. “For the most part that’s what he and I did for 11 years. Just about every time I threw it to him, it seemed like it was a touchdown. All I did was drop back and let the ball go. He always made a play on it, and it was impossible to overthrow Marvin because he was so fast.”

Yet Harrison had not been himself the last two years.

Despite finishing his Colts career with 1,102 receptions, second on the NFL’s career list, that 2007 knee injury forced him to miss 11 games and he was never the same.

Last year, he caught just 60 passes for 664 yards — his lowest career totals in a non-injury season.

In May 2008, police also interviewed Harrison about a shooting in his hometown of Philadelphia. An investigation later found that five of the six bullet casings came from a gun owned by Harrison, though charges were never filed.

The combination of his declining numbers, high salary and increasing age prompted the cap-strapped Colts to make one of their toughest decisions: releasing Harrison in February to save about $6 million.

It was a decision nobody wanted to see.

“Yeah, man, it is different, but life goes on,” Wayne said. “When I’m gone life goes on, too. You hate seeing Marvin gone, (coach Tony) Dungy gone, but if you worry about who’s not around, you will fall off. So you’ve got to go on.”

Harrison, who turns 37 later this month, still hopes to sign with another team. It’s not likely to happen until later this month at the earliest.

Meanwhile, Manning is going back to work.

He’s trying to get his timing down with Collie and with running back Donald Brown, a first-round draft pick who signed his contract in time to work out Monday. He’s learning the nuances of Caldwell, the Colts’ longtime quarterbacks coach who took over when Dungy retired in January.

And, yes, he’s turning his head to the left a little more now.

“That’s not something that you can get over right away, not only what both of those guys have meant to this team but to me,” Manning said. “Coach Dungy, what he has meant to all of us, all of our players and coaches, both professionally and personally and then Marvin, what he has done for my career. Like I said, it will be different.”