According to Andrew Marchand of the New York Post, ESPN is attempting to acquire Michaels from NBC Sports, where he still has two years remaining on his contract. Manning would be available, but the former quarterback has said he'd only join an announcing booth in the right scenario.
An experienced play-by-play analyst like Michaels could help Manning have an excellent transition into announcing.
Marchand reported "the network is strongly considering a change" from current analysts Joe Tessitore and Booger McFarland.
ESPN reportedly originally offered Romo a 10-year, $140 million deal, but he remained with CBS on a deal that will pay him more than $17 million per season, per Marchand.
The company's plan was to pair him with Michaels, although Manning could represent a suitable replacement.
The future Hall of Famer already has an ESPN+ docuseries "Peyton's Places" and is a well-known personality from his commercials, although he's yet to join an announcing booth after retiring in 2015.
If he does join Monday Night Football, ESPN could potentially pair him with current analyst and former Colts teammate Jeff Saturday.
Meanwhile, Michaels would only be able to move on if NBC grants him a release from his contract. However, ESPN let him go in 2006 and NBC has Mike Tirico available to replace the veteran announcer.
The 75-year-old announced Monday Night Football from 1986-2006 before moving to Sunday Night Football.