MANILA, Philippines - Boxing trainer Emmanuel Steward believes Filipino boxing icon Manny Pacquiao will have a difficult time against Puerto Rican boxer Miguel Cotto, should they ever have a rematch.

Pacquiao defeated Cotto in their 2009 fight, knocking him down in the third and fourth rounds. The referee stopped the fight in the final round, awarding Pacquiao a technical knockout (TKO) victory.

Cotto is coming off a dominant victory over nemesis Antonio Margarito, and he believes he can defeat Pacquiao in a rematch.

Steward did not say outright that Cotto can defeat Pacquiao, but said the Puerto Rican has "a good chance."

"(Cotto) is boxing better and not keeping his head down so much," Steward said in an interview with Examiner.com. "Now that he's not having to kill himself to make weight, if they fought at the proper weight, about 150 or more, I think he has a good chance."

"I think it would be a rough fight... It would be a tough fight for Manny," he added.

Steward, who trained Hall of Fame fighter Thomas Hearns, also believes that Cotto's future in boxing "looks very good" after putting together three impressive performances.

"I think he's had three good victories of some recognizable names, and in those fights, he's almost lost no rounds," Steward said. "The future looks very good for Miguel."

Top Rank chief executive officer Bob Arum, who promotes both Pacquiao and Cotto, has not made any indications that he is considering a rematch between the fighters.