MCU: 10 Fascinating Facts Behind Guardians Of The Galaxy (2014)
2. Iron Man Might've Had A Cameo, If Not For Downey Jr's Contract Talks
Iron Man met the Guardians of the Galaxy (or at least some of them) during Infinity War, but the meeting could well have happened sooner if things had gone to the initially reported plan.
It was previously reported that Iron Man 3's post-credits scene, rather than having Tony Stark talking to Bruce Banner, would've had him flying off into space and meeting the Guardians of the Galaxy, thus setting up their movie the following year, in which Robert Downey Jr would cameo.
Downey Jr, however, wasn't sure whether or not he wanted to continue as Iron Man, and as his contract expired with Iron Man 3, the scene was replaced with Banner. Of course, a couple of months after the movie's release, Downey Jr did sign a new deal for Avengers 2 and 3, and has been taking things on a movie-by-movie basis since then.