MANILA, Philippines–Manny Pacquiao has his eyes on a generational showdown with undefeated American Shakur Stevenson after the Filipino ring legend’s rematch with Floyd Mayweather Jr. was postponed indefinitely. According to BoxingScene, citing an “official” close to the situation, Pacquiao “is in advanced negotiations to return to the ring by year’s end,” possibly against the 29-year-old