By Mike Coppinger

A lot is riding on the line with Saturday's HBO bout between Juan Manuel Marquez and Mike Alvarado. The victor will be the mandatory to Manny Pacquiao's WBO welterweight title, and the riches that come with it.

"(Pacquiao) is up to fight the winner," Arum said on a conference call Tuesday. "I will offer the winner the fight with Manny and it's up to the winner to accept."

Marquez, of course, has already faced Pacquiao four times, going 1-2-1, though a case can be made for him winning all four bouts. Alvarado is coming off a brutal loss to Ruslan Provodnikov.

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