Ronnie's manager Matt Cohen tells TMZ ... Stephen Izzo had encountered "Jersey" producers three weeks before the fight and signed a release form to appear on the show -- a form obtained by TMZ.
Cohen claims Izzo realized he needed conflict to score screen time -- so he went home and concocted a plan to provoke Ronnie into a fight on camera ... and we all know how that went.
Ronnie's manager believes the release form proves Izzo "obviously wanted to be on the show" -- and was willing to do whatever it took to make that happen.
Izzo's currently suing Ronnie and MTV over the punch -- claiming, among other things, invasion of privacy and unauthorized use of his image.
Ronnie was indicted by a grand jury in New Jersey last month over the scuffle -- charged with one count of third-degree assault ... and he could face up to five years in prison if convicted.
We contacted Izzo -- but he refused to comment.