Manny Pacquiao said he will prove his detractors wrong once he steps inside the Las Vegas ring with international boxing superstar Oscar de La Hoya on December 6.

"This is no mismatch," said Pacquiao in a report posted on SportsNews.ph. "Some people are criticizing Oscar for picking on a small guy like me. Some are saying I'm taking the fight for the money. But on Dec. 6 I will prove all the critics wrong."

This is Pacquiao’s reply to concern being aired by some quarters that the Filipino is on the losing side against De la Hoya.

The Golden Boy is four inches taller and will be possibly 25 pounds heavier than Pacquiao on fight night. Both fighters agreed to meet at the 147-pound division.

The Filipino lefty, however, showed little concern over De la Hoya’s size as he cited that he will use his superior speed against the Mexican-American star.

"You have seen my previous fights and you know how Manny Pacquiao fights in the ring," he said.

Meanwhile, Pacquiao’s trainer Freddie Roach said he will use his De la Hoya experience in plotting their strategy against the Golden Boy.

Roach once trained as De la Hoya when the Golden Boy fought and lost a match to Floyd Mayweather, Jr. last year.

"I learned a lot during the eight-week period," Roach said about his stint with Dela Hoya, "and now I'm going to use it against him. I know his strengths and I know his weaknesses. We're going to take advantage of his mistakes."

De la Hoya admitted that Roach’s time with him last year is a "concern" but quickly added he is ready and focused for this fight.

"I am 35 years old, challenging a young, hungry, fast, explosive fighter like Manny Pacquiao," De la Hoya said.

"It's a huge challenge for me. But when I have everything to lose and nothing to gain, to me that's the motivational factor. I have to prove to myself that I can still do this. Manny Pacquiao, the heart that he has, the fire that he has, he's a big threat to me," he added.