Gennady Golovkin wants to "hurt" Saul 'Canelo' Alvarez in their much-anticipated rematch, which the Kazakh's promoter believes will be a bigger event than the original bout.

Golovkin and Alvarez had been due to meet for a second time on May 5, following their draw almost exactly a year ago.

But the fight had to be postponed after Canelo tested positive for the banned substance clenbuterol, which he blamed on contaminated meat eaten in Mexico.

Canelo served a six-month ban but Golovkin has been vocal in disputing his opponent's version of events, escalating tensions between the two fighters.

Promoter Tom Loeffler says Golovkin and trainer Abel Sanchez had no reservations about scheduling the rematch after Canelo's ban, but that being made to wait for his chance has given the WBA and WBC middleweight champion "an extra sparkle in his eyes".

"Gennady's position and Abel's position has always been if the Nevada Commission licenses Canelo and says that under their rules he's able to fight, and if VADA testing says that he's passed all of his tests, then there were no issues," he told Omnisport. 

"It's just when he failed the two tests in February, that's when everything fell apart. There were a lot of fans upset, who had booked tickets to Las Vegas for May 5 and they were upset at the cancellation.

"But we tried everything in our power to keep that fight together, or to keep that date together for Gennady, but with Canelo's suspension it wasn't possible.

"But here we are now. I think it's an even bigger fight with all the controversy, all the animosity on both sides, the clear dislike that each fighter has for each other and I think this makes it a much bigger event than the first time.

"Gennady doesn't need extra motivation to win a fight or defend his titles. This will be a record 21st title defence if he's able to defend his titles on Saturday.

"But you get the sense that he really wants to win this fight and hurt Canelo. Whereas before he just wants to win, even by knockout, but this one here you sense that extra sparkle in his eyes when he's training that he really wants to put the pressure on Canelo.

"And frankly he doesn't want to leave it in the judges' hands this time, he wants to hurt Canelo to the point where it's not going to go 12 rounds."

Loeffler also admitted the rematch almost collapsed during discussions between the two promoters.

"This was probably one of the toughest negotiations I've ever been involved with," he added. "It dragged out over a month between the percentage splits and the other terms.

"Naturally, in a huge fight like this there's a lot of different terms to negotiate but both sides dug in on their split.

"We were very close at the end but then Golden Boy set a deadline. We went past the deadline. Gennady, out of principle, said that he was firm on the split that he was demanding at the time, or that he would agree to, and we actually had the fight set with Billy Joe Saunders as a backup.

"When it went past the deadline I really thought this fight wasn't going to happen in September and then literally an hour later [Golden Boy president] Eric [Gomez] called me back and he made one last proposal, which I knew Gennady would accept because that's what he was looking forward to the whole time and we made a deal within five minutes."