Joshua Clottey of Ghana trains with the speed bag during a media workout in New York last Friday. Clottey is set to challenge Manny Pacquiao on March 13 in Las Vegas for the Filipino’s world welterweight title. (Reuters)

LOS ANGELES — Freddie Roach wouldn’t mind seeing Manny Pacquiao take out Joshua Clottey early.

“I have said that the fight will be long and that it’ll probably end late, like nine rounds but I would be very happy if Manny wins in one round,” Roach said on Thursday, the eve of his 50th birthday.

After seeing Pacquiao flex his muscles for eight rounds against two sparmates at the Wild Card Boxing Club in Hollywood, the bespectacled cornerman said he just can’t wait for the fight to take place.

Pacquiao and Clottey slug it out on March 13 at Cowboys Stadium in Dallas with the Filipino the overwhelming 5-1 favorite to retain his World Boxing Organization welterweight crown before an expected sellout crowd of 45,000.

Owing to Clottey’s huge advantage in size and durability, Roach said he doesn’t see the fight ending quickly, adding that “they’ll make Clottey quit,” even though nobody has done that before to the Ghana slugger.

Pacquiao has been ruthless to his sparring partners, something that gives Roach the confidence that Clottey will end up looking like Oscar De La Hoya and Miguel Cotto, fighters who withstood Pacquiao’s early assault but wound up getting stopped late in the bout.

Team Pacquiao leaves for Dallas on Monday.