Britain's Ashley Theophane will take on Pablo Cesar Cano on the Mayweather-Alvarez undercard on September 14.
On the most eagerly awaited night of boxing this year, Theophane will take on the one-time welterweight contender over 10 rounds at the MGM Grand Garden Arena.
The clash is the last of four to be finalised for the PPV event in America with Theophane (33-5-1) given his chance to shine after signing for Mayweather Promotions.
The 32-year-old would have kept the Lonsdale Belt outright if he had beaten Darren Hamilton in his third defence of the British title last year, but lost the light-welterweight strap by unanimous decision.
The mouth-watering clash between WBC and WBA light-welterweight champion Danny Garcia and Lucas Matthysse provides chief support to the main event, while the other fight sees Ishe Smith take on Carlos Molina.
Smith became the first native Las Vegan to win a world title when he beat Cornelius Bundrage for the IBF light-middleweight title.
He makes his first defence against Molina, who gets his first title shot at the age of 30.