"I don't know who's gonna get in there with him because I'm saying, he intimidating," Holyfield said to TMZ Sports. "He's a big guy, you already know he got big arms and stuff like that. He's got good range."
Holyfield added the six-time Pro Bowler "could be a good fighter."
Nobody can say Marshall is lacking in ambition.
In a since-deleted Instagram post in October 2019, the 36-year-old said he was aiming to be the heavyweight champion of the world and called out the likes of Deontay Wilder, Anthony Joshua and Tyson Fury.
Marshall reached the highest level of his profession by playing in the NFL. Former NBA star Nate Robinson proved excelling in one sport isn't immediately transferrable to another, though, when he suffered a second-round knockout to YouTuber Jake Paul.
While he might have Holyfield's endorsement, Marshall may want to work his way up the ladder before putting on the gloves against the best in the heavyweight division.