WBO welterweight champion Manny Pacquiao (59-6-2, 38 KOs) says he is still physically capable of getting down to the lightweight limit of 135-pounds.

Pacquiao has not been at lightweight since 2008, when he knocked out David Diaz.

Following the fight with Diaz, Pacquiao jumped up by two weight divisions to face Oscar De La Hoya at welterweight and he's been pretty much stationed in that division ever since. He weighed in as low as 142 and as high as the full division limit for his welterweight fights.

Pacquiao's trainer, Freddie Roach, believes his boxer's best fighting weight is at 140, the junior welterweight limit. He would like Pacquiao to take a big fight at junior welterweight against one of the big names in the lower weight divisions.

But Pacquiao says he can get down even lower if needed for a big fight.

"I can do even 135 pounds. It's easy for me. It would take two or three days to lose the weight," said Pacquiao.

Pacquiao, who is 38 years old, will return to the ring on Saturday night when he faces undefeated 2012 Australian Olympian Jeff Horn before a crowd of 50,000 at the Suncorp Stadium in Brisbane, Australia.

Age is factor says Pacquiao. He still feels as sharp as ever at this late stage of his career. The only issue Pacquiao faces, at this stage, is the amount of time needed to physically recover from those hard workouts.

"At my age, the body has responded quite well. I work just as hard I did when I was 25, I work as hard as I can, but the problem is recovery. When you are young you recover at night, but when you grow old you need more time," Pacquiao said.

Currently a senator in the Philippines, Pacquiao is planning to releases a series of books about his life before, during and after boxing.

"It will be two books, edition one and two and the two will connect. The first will talk about what it was like before boxing and the second, about what happened in boxing and after," Pacquiao said.