The ringside doctor SHOULD HAVE stopped the Tyson Fury fight based on the size of his gash ... but they let it go because Tyson is a huge star -- so says Otto Wallin.
The Swedish fighter tells TMZ Sports ... if the tables were turned, the doctor would DEFINITELY have called the fight because the wound was massive and posed a real medical danger.
"If it was someone else, they probably would have stopped it," Wallin said while hanging at a Vegas pool party.
Still, Wallin is being praised for his gutsy performance ... taking Fury to the 12th round despite being a massive 30-1 underdog. Dude fought his ass off.
There was one questionable moment when Wallin appeared to rake Fury's face after an exchange in an apparent effort to widen the cut on Tyson's face.
We asked Wallin if he felt the move was dirty ... and he sorta copped to it.
"He was using dirty tactics too and I'm not gonna let someone do that to me, without me answering back with some dirty tactics," Wallin said.
"This is boxing. It's a fight and you gotta do everything you can to win."
Despite the cheap shots, Wallin says Fury came to his locker room after the fight to congratulate him on the performance ... "[He] showed some respect."
So, what's next for Wallin? He wants a rematch with Fury but knows he probably won't get it any time soon because Tyson has his sights set on a rematch with Deontay Wilder.
"After that, maybe I could get the winner. That would be great, fight for the world title."
Until then, he's got a message for Fury ...
"I wanna say it was a good fight. Thank you for the opportunity and I hope we can do it again."