Manny Pacquiao is about to enter the critical phase of his training for his bout with David Diaz.

“My training is getting harder and harder and in the coming days, the number of rounds of sparring will go up,” said Pacquiao from Los Angeles where he has been training for over two weeks now.

His fight against Diaz will be on June 28 at Mandalay Bay in Las Vegas.

“Last Monday, I sparred eight rounds and in the next few weeks, the number will go up further. Two weeks before the fight, I will spar 12 rounds in a day,” added Pacquiao.

The Filipino fighter has at least four sparmates at the Wild Card Boxing Club three times a week under the supervision of Freddie Roach.

With exactly 30 days before Pacquiao go up the ring to attempt to knock the World Boxing Council (WBC) lightweight crown off Diaz’s head, tight security will be enforced at the Wild Card soon as fans and even friends of the Filipino fighter will no longer be allowed to get inside while Pacquiao is working out.

This has been the case in most of Pacquiao’s high-profile fights since Roach is wary of videos clandestinely taken during these critical times might end up being smuggled to Diaz’s training camp.

While Pacquiao is going at it like a madman, Diaz is also heavily immersed in training, having been reporting to the JABB Gym in downtown Chicago since April 19.

After this weekend’s promotional tour in the Bay Area where Pacquiao and Diaz will be in attendance, to hype the card dubbed “Lethal Combination”, the training of the two southpaws should intensify in the next couple of weeks.

Pacquiao, 29, has declined to make a prediction, while Diaz, 31, has been compelled to say that he won’t allow his belt to be taken away from him.