Briton Khan, who had been linked to a massive UK clash with Brook in the summer, will step up two divisions from welterweight to middleweight in order to be the first challenger to Canelo’s WBC crown.
Canelo took the title from Miguel Cotto last November and is known to be much heavier than the 160lb limit once he rehydrates after a pre-fight weigh-in.
Hearn believes Khan is facing a mammoth task and faces having to move on in a bid to find an alternative opponent once IBF 147 pound champion Brook follows through with his mandatory duties against Kevin Bizier.
“I got the news about Canelo v Khan at the weekend and I’m surprised at the fight,” Hearn exclusively told World Boxing News.
“I think Canelo will be around 170 pounds on fight night and Amir has only just moved to 147. I think Canelo will be much too heavy.”
Obviously, Tuesday shock announcement puts an end to Brook v Khan in the immediate future and Hearn will focus his efforts on the likes of Americans Keith Thurman and Danny Garcia for the Sheffield man.
“I’m disappointed we couldn’t deliver Brook v Khan for the British public but you can’t force another man to fight.
“We were close, but now after Bizier we must fight one of the other champions,” said Hearn.