Former Indianapolis Colts head coach Tony Dungy has expressed his belief that Denver Broncos quarterback Peyton Manning will return to the NFL for the 2015 season.

Manning refused to rule out retirement from the game following his side's defeat to the Colts as he struggled to throw the ball deep downfield and also reportedly sustained torn quadriceps.

However, Dungy, who coached Manning for seven seasons at the Colts, is confident that the 38-year-old has at least one more season left in the tank before he calls time on his career.

"It's the first time I've ever heard him talk about life after football, but I didn't get the sense that that was right away," Dungy told the Indianapolis Star.

"I think he's thinking down the road a little bit. He was talking about his guys and how much he enjoys his team and teammates and I just think he's planning on being back."

Manning threw for 4,727 yards along with 39 touchdowns to 15 interceptions in the 2014 season.