The quarterback has also agreed to a new deal that will have him take a $4 million pay cut, the first of his career, reports the Post. ESPN's Chris Mortensen and Jeff Legwold first reported the pay cut.
Manning, who was due to earn $19 million in both 2015 and 2016, will now earn $15 million in each.
"I don't talk about my contract. I never have in 18 years and I'm not going to start now," Manning said Wednesday. "I've been working real hard and I'm excited to be back with the Denver Broncos. Can't wait for April 13 to get here when the team can finally come together. I'm excited to get to work and get to know the new coaches and looking forward to trying to make 2015 a special year."
Manning, who turns 39 this month, has not officially announced his status for next season. However, Mortensen previously reported that Manning is physically and mentally ready to return to the field in 2015.
New Broncos head coach Gary Kubiak said last month there was "no doubt" the team wants Manning back next season.
Manning played the last month of the 2014 season with a quadriceps injury and is four seasons removed from a fourth neck surgery. He has spent recent weeks working with trainer Mackie Shilstone, who is known for his work with stand-out performers in the later years of their career.
Manning finished fourth in the NFL in passing yards with 4,727 last season, his third year with the Broncos. He threw 39 touchdowns and 15 interceptions.
- Molly Geary