(CNN) -- The worst secret in boxing is out of the bag: "Sugar" Shane Mosley is the most likely opponent for Manny Pacquiao's next fight.
The 39-year-old American boxer used Twitter to announce that discussions between the two camps are at an advanced stage, with confirmation expected in the next 24 hours.
"Just excited about the fight with Pac [Manny Pacquiao]. I know you're going to be there," he tweeted to former world heavyweight champion Lennox Lewis on the social networking website.
"The ink hasn't dried yet but it's pretty much a go."
Speculation has mounted over who would fight the Filipino eight-division world title-holder on May 7 at the MGM Grand in Las Vegas, with Juan Manuel Marquez mooted as another possible opponent.
But in a subsequent interview with the Los Angeles Times, Mosley confirmed that he would meet with Pacquiao's representatives on Tuesday to finalize a deal.
"We've already discussed the fight about three to four weeks ago, so now we'll go over it again," said Mosley.
"Both sides just need to commit to what we've talked about and then I think we're done."
Pacquiao's trainer Freddie Roach had earlier ruled out Marquez while, at the same time, insisting on an important caveat if Mosley was indeed chosen.
"[Mosley] won't be an easy fight for Manny," Roach told assembled reporters in the Philippines, where he was celebrating Pacquiao's 32nd birthday.
"He can punch with either hand. But if the fight pushes through, I'll insist on a drug test. He's been known to take steroids and it shows in his body."
Roach was referring to a 2003 U.S. grand jury submission by Mosley where he admitted using EPO, a performance enhancing drug, as he prepared to fight Oscar De La Hoya.
But Mosley never tested positive, and denied knowing what it was or that it was illegal.
"I'm disappointed that this is coming out again, four years after I've been to the grand jury and gave my truthful testimony," Mosley said in a 2008 statement, issued after the allegations first came to light.
"I even took a lie-detector test back then to let everyone know that I wasn't trying to be an unfair fighter."
But it looks like Mosley will now have a chance to fight arguably the best pound-for-pound boxer in the sport to prove his detractors wrong.