David Diaz knows he will be in for a tough night with Manny Pacquiao on June 28.

“I have already been running and shadowboxing,” Diaz said yesterday from his Chicago home.

“I am very excited to fight Manny Pacquiao.”

While Top Rank has yet to make a formal announcement regarding Diaz’s defense of his World Boxing Council (WBC) lightweight crown at Mandalay Bay in Las Vegas, the fight is already a done deal as Pacquiao and trainer Freddie Roach have already discussed plans for training camp starting the first week of May.

Diaz said his training will go full-blast as soon as he puts his signature above the dotted line.

“But I am keeping myself in good shape,” said Diaz, who holds a 34-1-1 win-loss-draw card with 17 knockouts.

In his last outing last March 15, Diaz mauled Mexican Ramon Montano, one of Pacquiao’s sparring partners.

But Diaz is aware that he will have his hands full against somebody like the 29-year-old Pacquiao.

“We’re getting sparring partners who are southpaws who will emulate what Pacquiao does in the ring.

Pacquiao throws a lot of punches and we are going to find sparmates who are like Pacquiao,” he said.

Although he hasn’t been to the gym, Diaz will report to the JABB Boxing Gym in Chicago, a reputed haven for top professionals and fitness freaks living in the area.

As to his chances of derailing Pacquiao’s bid to become the first Filipino fighter to win the world lightweight championship, Diaz was not tempted into saying something nasty as some fighters would if they are dared.

“I just know what I can do in the ring, that’s all,” said Diaz.

And his message to Pacquiao?

“Well, let’s just please the fans.”