The Oscar winner has grown close to Krasinski since working with his actress wife Emily Blunt on 2011's The Adjustment Bureau, and they recently sat down to write the screenplay for the drama Promised Land together.
And Damon was so impressed with the 33 year old's work, he insists Krasinski - who is best known for his role on the small screen comedy - has what it takes to follow in the footsteps of Tv star-turned-movie icon Clooney, who first found fame on medical series Er.
Damon tells U.S. breakfast show Today, "He's just a really talented guy and people don't even (know it yet). I knew him from The Office and was a fan of his and the show, but the scope and breadth of his talent is so much more vast than that and as I got to know him I really wanted to work with him...
"It's kind of similar to when I met George Clooney years and years ago and everybody knew him from... Er. But Steven Soderbergh did a movie with him (Ocean's Eleven) and instantly formed a company with him and everybody in Hollywood was going, 'What is Steven Soderbergh doing forming a company with the guy from Er?' What Steven knew is what... George was capable of and I think the same is true for John."