Gennady Golovkin will be fuelled by a desire for justice when he puts his world middleweight titles on the line against Saul 'Canelo' Alvarez in their eagerly-awaited rematch in Las Vegas on Saturday night.

Golovkin was left stunned when their first bout in September last year was declared to be a split-decision draw - then kept waiting for his second shot after Alvarez failed a drugs test.

All of which has left the big-punching Kazakh to lose respect for his middleweight rival, adding further spice to a contest which is regarded as one of the biggest in the sport.

Golokvin told the media this week: "I have lost respect for him. It changed after the doping scandal.

"After the first fight I said, 'thank you for the fight, it was a great fight'. He said the same. We were friendly. But after doping? No. This is a terrible situation and right now we have only business."

Alvarez's six-month ban after testing positive for clenbuterol - he claimed the positive test came from eating contaminated meat - scuppered the first prospective rematch date earlier this year.

Golovkin marked time with a stoppage win over Vanes Martirosyan and will head into the rematch eager to leave nothing to chance, having started sluggishly first time round.

For his part, Alvarez says he too will adopt a different tactical approach. Showing he could stand up to Golovkin's ferocious power, the Mexican still faded badly through the middle rounds suggesting stamina could prove a major factor.

"I have made a complete and radical change and you will see this on Saturday," Alvarez told media.

"I am bothered by all the stupid things (Golovkin's team) have been saying and I have been using it as motivation for this fight. Maybe they believe what they say, maybe it is to get me mad - but it has worked."