JUAN Manuel Marquez on Wednesday acknowledged that Manny Pacquiao has indeed improved but insisted he has also become a much better fighter and vowed their rematch will be nothing like their first encounter.

Almost four years ago, Pacquiao knocked Mar-quez down three times in the opening round only to allow Marquez to fight back and survive 12 rounds to force a draw.

The two square off anew on March 15 (March 16 in Manila) at the Mandalay Bay Resort and Casino in Las Vegas, with the World Boxing Council super featherweight belt of Marquez at stake.

"It will be a totally different fight," said Marquez in an article posted on fightnews.com.

"It's been four years. I'm stronger now. I think I have more speed," said the Mexican, seemingly responding to Pacquiao's earlier declaration that he has transformed into a "smarter" fighter.

"I'm a better fighter, a more technical fighter and I have more stamina. In the first fight, Manny Pacquiao got tired," added Marquez, who held the IBF and WBA featherweight titles when he first faced off with the flamboyant Filipino.

"He's become better and he has a great trainer," Marquez said, referring to Pacquiao's world renowned coach Freddie Roach.

"He's a very fast fighter. He's a very strong fighter. a very quick fighter. He has a strong punch."

Marquez, 34, however, said he has thoroughly studied Pacquiao's style and claimed he knows how to deal with the Filipino's powerful left hand.

"We know Manny Pac-quiao's left hand is like a bullet. It's very fast, very powerful," Marquez said.

"You gotta be alert from the first round all the way to the end," he said.

Marquez also said he is eager to get it on with Pacquiao, since the Filipino has earned a reputation of being a "Mexican killer" after dominating a host of Mexican prizefighters, including superstars Marco Antonio Barrera and Erik Morales.

"More than pressure, there's pride and motivation," Marquez said. "It's a big responsibility for me, taking this fight."