By Miguel Rivera

Former undisputed heavyweight champion Buster Douglas, who in 1990 secured the biggest upset in boxing history by becoming the first man to defeat Mike Tyson, believes Mexican superstar Saul "Canelo" Alvarez (49-1-2, 34 KOs) was capable of beating Gennady Golovkin (37-0-1, 33 KOs) - but he simply didn't do enough to win. 

There is an old saying in boxing, that a challenger must take the title from the champion. Douglas felt Canelo did not do enough to take the title from the champion.

Canelo challenged Golovkin, who holds the IBF, IBO, WBA, WBC middleweight titles, last month at T-Mobile Arena in Las Vegas. After twelve rounds of action, the contest ended in a controversial draw.

There are now discussions to stage a rematch in 2018. The most likely date is May 5 - as part of Cinco De Mayo weekend. Las Vegas would once again become the frontrunner to stage the contest.

Douglas felt Canelo had the edge in the later rounds, but took his foot off the gas and didn't press enough. He says Canelo should have let his hands go and gone for the kill in the championship rounds.

If the rematch goes down, Douglas has advised Canelo to do a lot more if he intends to walk away with the titles that night.

"When you're challenging for a world title, you have to beat the champion. Canelo was doing very well, and I'm not surprised that he did, because of the skills that he has - but you have to beat the champion... you can not just let things happen," Douglas said.

"I think that's why it ended in a draw. That's why Canelo's corner was shouting at him from the bottom of the ring ... because they knew he had to go for it. When you're in that situation [and the fight is on the table], you have to finish the job."