(Reuters) - Manny Pacquiao said on Wednesday that Cuban Yordenis Ugas, who agreed to put his WBA welterweight championship belt on the line against the Filipino southpaw on short notice, is not to be underestimated.

Pacquiao was preparing to fight WBC and IBF welterweight champion Errol Spence, Jr. on Aug. 21 in Las Vegas but a retinal tear forced the American to withdraw and on Tuesday Ugas was announced as Pacquiao's new opponent.