Anthony Joshua says Jarrell "Big Baby" Miller shouldn't worry about that "bitch ass rematch clause" in their fight contract ... because after AJ beats him down, Miller won't want to do it again anyway!
The UK boxing superstar was in a GREAT mood in NYC on Wednesday -- despite getting pushed around by Miller during their press conference on Tuesday.
When asked if Miller crossed a line when he put his hands on Joshua, the heavyweight champ told Adam Glyn it's "just playground stuff" ... and Miller will get his beating on June 1.