Manny Pacquiao has confirmed his March WBO welterweight title defence against Joshua Clottey.

His trainer Freddie Roach however, continued to accuse Floyd Mayweather Jr of avoiding his fighter.

Pound-for-pound number one Pacquiao, 31, was set to fight unbeaten Mayweather, 32, on March 13 until negotiations broke down when the two camps failed to agree on pre-fight drug-testing protocols.

The fight was seen as an unofficial bout to decide the best boxer on the planet, Mayweather (40-0, 25 KOs) having previously held that status by general consensus before going into a temporary retirement at the end of 2007 following his victory over Britain's Ricky Hatton.

In the American's absence, Filipino fighter Pacquiao (50-3-2, 38 KOs) assumed the mantle with standout victories over Oscar De La Hoya, Hatton and most recently Miguel Cotto, all bigger men in weight divisions above his natural domain.

And, while Pacquiao has switched his focus to fighting Ghana's Clottey (35-3, 20 KOs) on March 13 at the Dallas Cowboys' stadium in Arlington, Texas, his trainer is still holding out hope of a fight against Mayweather, who beat De La Hoya when Roach was in his corner in May 2007.

"I want to see it," Roach told ESPN following an extravagant press conference at Cowboys Stadium.

"I want to see Manny kick (Mayweather's backside), you've got to believe me.

"The thing is, he won't give us that opportunity."

Roach said Mayweather, who is now being linked with a fight against WBA welterweight champion Shane Mosley on the same date as Pacquiao-Clottey in Las Vegas, had a track record of avoiding the best fighters in his division.

"He ducked (Antonio) Margarito when he was number one, he ducked Shane Mosley and now he's ducking Manny," he said.

"He picks and chooses his opponents, let's face it."

Pacquiao and Clottey had earlier been introduced to the media at Cowboys Stadium, wearing Dallas Cowboys shirts and flanked by the team's famous cheerleaders.

"I have never been in a stadium like this," said Clottey, whose last fight was a split decision defeat to Cotto at Madison Square Garden last June.

"I like Manny, he's my favourite fighter. It's going to be a great fight."

Pacquiao returned the compliment, adding: "He's a good fighter, he's a top fighter and he's bigger than me.

"I have to prepare hard for this fight and train hard and focus."