Manny Pacquiao declared he is ready for the biggest fight of his career and vowed fans will see the killer instinct he was best known for, which he failed to display in his previous fights.

Pacquiao, who will face Floyd Mayweather on Saturday at the MGM Grand Arena in Las Vegas, said that he is happy his killer instinct is back. He admitted he lacked the desire to dominate his opponent in his previous fights, but Saturday night's fight against Mayweather will be a different story.

"I'm so happy because the feeling of the killer instinct and the focus that I had years ago is back," Pacquiao said via BoxingScene. "I haven't felt like this in my recent few fights, but now I feel different."

Pacquiao, who holds a 57-5-2 record with 38 victories by way of knockout, is coming off a lopsided unanimous decision win against Chris Algieri in November. The Filipino boxing icon knocked Algieri down six times in the fight, but he failed to win by stoppage.

Pacquiao, who is the reigning World Boxing Organization welterweight champion, has not scored a knockout win since stopping Miguel Cotto in the 12th round of their title fight in November 2009, which came after knocking out David Diaz, Oscar De La Hoya and Ricky Hatton, respectively.

Most analysts are still convinced Mayweather will win against Pacquiao in their upcoming fight on Saturday night, but Pacquiao said that he is ready to prove his doubters wrong.

"I'm eager to show something, especially because I'm the underdog," Pacquiao said. "Every time I've been the underdog, like against Oscar De La Hoya, it's a different feeling and I'm so glad that it's back. This is one of the most important fights for my boxing legacy. I want to make this fight for my boxing legacy. I want to win, that's my goal."

The former pound-for-pound king said he is 100 percent prepared to face Mayweather as he will step on the ring equipped with more than one fight plan. Pacquiao said he is ready if Mayweather decides to engage against him, but he is also prepared if the Grand Rapids native decides to focus on utilizing his wall-like defense.

Hall of Fame trainer Freddie Roach also confirmed they will be ready for whatever Mayweather will throw in the Cinco de Mayo showdown. The veteran trainer is also convinced Mayweather will not be able to keep in step with Pacquiao because he thinks his fighter is faster and has more power than the undefeated world champion.

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