Jarrell "Big Baby" Miller says Anthony Joshua forced a "bitch ass rematch clause" into their fight contract ... telling TMZ Sports, he's already preparing to knock the dude out TWICE!!!
We spoke with "Big Baby" after his clash with Joshua in NYC on Tuesday -- where Miller straight SHOVED Joshua while promoting their June 1 championship fight at Madison Square Garden.
Miller knows he's the underdog in the fight ... but says the critics can "kiss my ass" -- telling us he's 100% confident he'll hand Joshua his first L when they throw down.
There's a lot of trash talk in this clip too -- Miller says a bunch of AJ's wins (from early in his career) were "given to him" by corrupt refs who would stop fights early to ensure a Joshua victory.
In other words, Miller says AJ's perfect 22-0 record is a sham -- and he's looking to expose Joshua in a big way.
Miller has an impressive resume too -- he's 23-0-1 -- and famously knocked out TWO DUDES IN 6 WEEKS in 2018.
He KO'd Tomasz Adamek in the 2nd round of their Oct. 6 fight -- and then took down Bogdan Dinu on Nov. 17.