As has become tradition on Cinco de Mayo weekend, the boxing world is preparing for another huge showdown -- just not the one most were expecting to see.

Undefeated middleweight champion Gennady Golovkin will be stepping into the ring against Vanes Martirosyan (36-3-1, 21 KOs) on Saturday night, but the last-minute replacement isn't who many expected to see face off with GGG. Lineal middleweight champ Canelo Alvarez was forced to withdraw from his highly anticipated rematch with Golovkin following a pair of failed drug tests leading up to the fight.

Now, one important aspect of this fight to keep in mind is that only GGG's WBA and WBO middleweight championships will be on the line. With Martirosyan not being recognized by the IBF as the No. 1 contender in the division, a defense of that belt is off the table. 

While the scheduled fight with Canelo is not going down on Saturday as originally anticipated, all eyes will be on this fight to see whether the polarizing GGG can remain an unbeaten warrior. Should he pull off yet another win in his professional career, then given the six-month time period of Alvarez's suspension, things should be lining up for the rematch we were all waiting for this September.

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Below is all the information you need to catch the bout between GGG and Martirosyan on Saturday, and be sure to check out CBS Sports' prediction for the middleweight showdown. 

GGG vs. Martirosyan viewing information

Date: Saturday, May 5
Time: 11 p.m. ET | Location: Stubhub Center -- Carson, California
Live stream: HBOGo | TV channel: HBO (check local listings)