Manny Pacquiao is being lined up to fight Timothy Bradley at the MGM Grand in Las Vegas on June 9.
Bob Arum, whose Top Rank promotes both fighters, says Pacquiao will put his WBO welterweight title on the line if the right financial terms are agreed.
"I'm very optimistic I'll get it done, but right now it's just not done," Arum told USA Today.
With Floyd Mayweather Jr announcing last week that he would face Miguel Cotto on May 5, any immediate prospect of a megafight with Pacquiao disappeared.
And now the Filipino superstar (54-3-2) appears likely to take on the unbeaten Bradley (28-0) instead.
Arum says he hopes to complete a deal by February 18, when Pacquiao will be in Vegas to attend a 70th birthday celebration for Muhammad Ali.
"I can plan to do the (press) tour with Manny and Bradley right after the 18th because I don't want Manny to come over here for (the Ali celebration) and then go back and bring him over again," Arum said.
"It's a long trip so I'd like to knock it off while he's here. My goal is to get the thing done in the next few days."
Pacquiao is coming off two below-par performances - a tepid points victory over Shane Mosley followed by what many saw as a highly fortunate decision against Juan Manuel Marquez.
Bradley meanwhile stopped Joel Casamayor in eight rounds on the undercard for Pacquiao/Marquez III.
