Manning, 39 next month, is due a $19 million salary in both 2015 and 2016. He made $20 million in each of the past two seasons.
Earlier this month, new Broncos head coach Gary Kubiak said there was "no doubt" the team wants Manning back in 2015. No official announcement has been made about Manning's status, perhaps due in part to the contract discussions.
The Broncos did not formally interview any quarterback prospects at the NFL scouting combine last week, reports the Post. The Broncos have Brock Osweiler and Zac Dysert at quarterback behind Manning, if he returns.
Manning played the last month of the 2014 season with a quadriceps injury and is four seasons removed from a fourth neck surgery.
"No doubt I want him to be (our quarterback). I feel good about where we are right now. It's just time," Kubiak said earlier this month, according to the Post.
Manning finished fourth in the NFL in passing yards with 4,727 last season, his third year with the Broncos. He was also second in passing touchdowns (39) and fourth in passer rating (101.5).
The Broncos went 12-4, winning the AFC West before losing to the Indianapolis Colts in the divisional playoffs.
- Mike Fiammetta