Indianapolis quarterback Peyton Manning walks the sideline during the Colts' preseason game against Buffalo on Sunday in Indianapolis.

Indianapolis ? More than a month after having knee surgery and enduring weeks of rampant speculation about whether the injury was worse than first feared, two-time league MVP Peyton Manning finally provided his doubters with one emphatic answer Tuesday: He’s back, right on schedule.

“This is a significant step for me to get back out on the practice field,” Manning said before throwing and running with teammates. “If things go well, as we expect they will, then I hope to be full go next week and ready for the season opener.”

Manning will be limited in practice initially after being activated from the physically unable to perform list.

Coach Tony Dungy said the Colts will be cautious with the franchise quarterback during this short week – Indy played Buffalo on Sunday night and faces Cincinnati on Thursday – before giving him a full complement of snaps next week.

“We’re going to monitor him and (rookie tight end) Tom Santi, who will start practicing today,” Dungy said. “So we do have a pitch count on those guys.”

It’s been a crazy month for Manning, the Colts’ iron man who has never missed a start in his 10-year NFL career.

He was instructed by doctors not to report to training camp with his teammates July 24, 10 days after having surgery to remove an infected bursa sac from the left knee. Team officials said it would take Manning four to six weeks to recover, and the six-week anniversary came Monday when the Colts did not practice.

Still, local radio talk shows, bloggers and fans continually questioned Manning’s whereabouts and readiness even after Dungy said July 29 that Manning had arrived in Terre Haute, Ind., the Colts’ training camp site.

When Manning didn’t appear at any practices or games, the doubts increased. A local television station ran what appeared to be a cell phone photo of Manning wearing a brace on his right knee – a photo Manning later called not true. Late last week, a national blogger suggested Manning had a second surgical procedure on the right knee, something Manning would not confirm Tuesday.

“I think it’s somewhat irrelevant because of where we are today, and I kind of like to keep you guys guessing,” Manning said, drawing laughter. “I never really like talking too much about an injury because if you play well, they say ‘Man, look how tough he is.’ And if you don’t play well, they say ‘That’s the reason.’ “

Manning’s return has taken on even greater significance given the Colts depleted situation at quarterback.