Floyd Mayweather Jr. (l.) and Manny Pacquiao.

MANILA — WBO welterweight champion Manny Pacquiao concludes the second trilogy in his career when he takes on Juan Manuel Marquez at the MGM Grand Garden Arena in Las Vegas on Nov. 12 but his trainer Freddie Roach said recently before he hangs up his gloves, there could be another three-part series in the offing — against Floyd Mayweather Jr. no less.

Pacquiao’s first trilogy was with Erik Morales.

It began with “El Terrible” winning a unanimous 12-round decision in 2005 then Pacquiao evened up matters with a 10th round stoppage a year later.

In the rubber match in November 2006, Pacquiao dealt Morales a resounding beating and won by a third round knockout.

The loss to Morales was Pacquiao’s third after Rustico Torrecampo in 1996 and Medgeon 3-K Battery in 1999 and he hasn’t been beaten since.

Pacquiao now has a streak of 14 straight wins.

Then came Marquez.

They fought to a split draw in 2004 although it should’ve been a win by split decision for Pacquiao as judge Burt Clements made an irreparable mistake on his scorecard in the first round where Marquez was decked thrice.

If Clements scored it 10-6 instead of 10-7, Pacquiao would’ve won by a split verdict.

Clements admitted the error but under boxing rules, it could not be reversed.

The fighters met again in 2008 and this time, Pacquiao took a split 12-round decision on the strength of a third round knockdown.

The third encounter will settle the issue of superiority once and for all.

Roach said Pacquiao is running out of opponents in the 147-pound division.

WBO lightwelterweight champion Timothy Bradley, 28, was recently signed to a contract by Top Rank and is being touted as Pacquiao’s opponent after Marquez.

Bradley will be showcased in a title defense against Cuban veteran Joel Casamayor in the undercard of the Pacquiao-Marquez mainer next month.

But Roach is no Bradley fan.

“I think he’s involved in a lawsuit with two promoters,” said Roach.

“Besides, he’s got to earn the fight with Manny. Bradley’s not well known. It’s premature to even consider him fighting Manny.”

Roach said Mayweather’s recent victim Victor Ortiz could be a candidate.

“I remember Victor sparring with Manny and they went at each other for two days until we stopped it because Ortiz was like 20 or 30 pounds heavier,” said Roach.

“I thought he had a good fight plan against Mayweather. He wanted to rough him up and get Mayweather’s corner all riled up like in the Zab Judah fight. After he butted Mayweather, Ortiz didn’t stop apologizing. On his third apology, Mayweather whacked him. I probably would’ve done the same although the referee (Joe Cortez) gave no signal to box. You’ve got to protect yourself at all times in the ring. Maybe, Ortiz should’ve butted Mayweather some more. If Manny fought Mayweather instead of Ortiz, he wouldn’t resort to those tactics. He wouldn’t have to.”

As for Amir Khan, Roach said the WBA lightwelterweight king will likely get a crack at Mayweather ahead of Pacquiao.

“Will Manny ever fight Amir?” wondered Roach.

“My two fighters are really friendly with each other. I don’t think they’ll ever fight but the thing is we’re running out of opponents and you can never say never in this game.”

Another option is WBA welterweight champion Vyacheslav Senchenko of Ukraine.

The hitch is Roach also trains Senchenko who has a 32-0 record, with 21 KOs.

If ever Pacquiao and Senchenko face off to unify the WBA and WBO titles, Roach said he’ll work the Filipino’s corner.

“The Ukraine people haven’t seen Manny and Senchenko’s promoters are very wealthy,” said Roach.

“His promoters control the coal and metal mines in the country. Manny could fight Senchenko in Ukraine for a lot of money. In the event they meet, Manny will win easy. I remember legends like Sugar Ray Robinson when in the course of winding up their careers, they would go to fight in different countries and earn big purses. If Manny wants to do that, Ukraine would be a good destination.”

During a recent visit to Manila, Top Rank chairman Bob Arum said Pacquiao confided that he plans to retire at the end of 2013, meaning he’ll sign for four more fights after Marquez.

Roach said the last three fights could be against Mayweather — of all people.

“You know, obviously, everyone wants Mayweather,” said Roach.

“Of course, we’re all getting a little tired of hearing his name because he doesn’t want to fight Manny. But hopefully, that fight will happen. That fight is so interesting, it could end up being a trilogy. Actually, it could be the last three fights for Manny, if the fight goes as we see it because they’re both very, very good fighters so it’s a fight we want.”

Roach said Mayweather has slowed down and is easier to beat now.

“There’s nobody out there for Manny anymore,” he said.

“Manny might just end up fighting Mayweather after all.”

Roach said he plans to bring a Filipino trainer Marvin Somodio to the Wild Card Gym in Los Angeles.  

He met Somodio in Baguio during Pacquiao’s recent workouts.

“He was a former amateur fighter,” said Roach.

“He did mitts with Alex (Ariza) and he’s a quick learner. I taught him how to wrap and he wraps just like me now. I need an assistant at Wild Card and I’m thinking of bringing Marvin over. He stretches well, too. I’ll send him a letter of invitation to the U.S. so he can show it to the Embassy when he applies for a visa.”