🚨🚨 MAJOR BEEF ALERT 🚨🚨
A.J. McKee and Patricio Pitbull -- Bellator Featherweight Grand Prix finalists -- do NOT like each other, and it all goes back to ... an autograph?!
"I actually asked [Pitbull] to sign a newspaper," A.J. tells TMZ Sports.
But, instead of just signing the paper ... Pitbull had other ideas, and McKee is PISSED.
"He done crossed my whole face out, picture out. So, I'm f****** him up for that like. Like I lost a lot of respect for him because of that."
And, McKee says he thinks Pitbull's shook.
"I'm in his head so f*****g heavy!"
A.J. and Patricio are the last 2 men standing in a tournament that started with 16 of the best 145-pound fighters in Bellator.
McKee has never lost ... winning all 17 of his Bellator fights -- many of them with ease.
Meanwhile, Pitbull is a legend. He's 32-4 and has wins over Michael Chandler and Juan Archuleta -- to name a few. Patricio is also a double champ ... holding the 145 and 155 lb. titles.
The featherweight title's on the line, but arguably more important is the million-dollar prize!!
We asked McKee what he was gonna do with the cash ... and let's just say this isn't the 1st time he's thought about the 7-figure check being deposited in his bank account.
"Oh, I spent it already bro. It’s spent already. I’m paying off my dad's house. I'm buying a [Porsche] GT 2RS. I need a Porsche in my driveway, man."
FYI, A.J.'s dad is Antonio McKee -- a veteran MMA fighter.
The championship fight goes down Saturday night ... personal beef, a title, and a million dollars are all that's on the line.