The four-city media tour to promote pound-for-pound king Manny Pacquiao's welterweight title defense against Shane Mosley kicks off Feb. 10 in Los Angeles, followed by stops on Feb. 12 in Las Vegas, Feb. 14 in New York and Feb. 15 in Washington, D.C.
But while the tour details are being finalized, Top Rank is also working on the Showtime PPV undercard, which could include a rematch of the 2010 ESPN.com fight of the year, the return of former middleweight champion Kelly Pavlik and a Puerto Rico vs. Mexico rivalry title bout.
The card is scheduled for May 7 at the MGM Grand in Las Vegas.
The co-feature in the works would match lightweight titlist Humberto Soto (54-7-2, 32 KOs) against Urbano Antillon (28-2, 20 KOs) in a rematch of their epic Dec. 4 slugfest, which Soto won via tight unanimous decision.
"There's no paperwork done yet, but the sides are aware of it and have [verbally agreed to the rematch]," Top Rank's Carl Moretti told ESPN.com Thursday. "We've talked to both sides and the camps are both up for the date and we're trying to get it closed up."
Antillon suffered a nose injury in the fight with Soto, but is expected to be ready to go in May, Moretti said.
Pavlik (36-2, 32 KOs) has not fought since losing the middleweight championship to Sergio Martinez last April. He pulled out of a comeback fight scheduled for Nov. 13 on Pacquiao's last undercard and checked into an alcohol rehabilitation clinic for the second time. He spent two months at the Betty Ford Center before coming out in early January.
"He's itchin' to fight," Moretti said.
Moretti said Top Rank matchmaker Bruce Trampler will visit Pavlik on Tuesday in his hometown of Youngstown, Ohio, "to see if everything is in order."
As soon as Pavlik came out of rehab, Top Rank chief Bob Arum promised Pavlik a spot on the Pacquiao-Mosley undercard if he wanted to fight and was ready.
"All indications are that Kelly would like to take advantage of that," Moretti said, adding that there has been no discussion yet of a specific opponent.
Cameron Dunkin, Pavlik's co-manager, said Pavlik is planning to fight on the card.
"The idea is that is he going to fight on May 7," Dunkin told ESPN.com. "We're just taking it one step at a time, but he's scheduled. He's terrific. He's working out and very happy, spending time with his family. Everything is wonderful right now."
Although Pavlik has gone back and forth about whether he would remain at middleweight or move up to super middleweight, Dunkin said he is moving up to the 168-pound super middleweight division.
"I would think he will fight at 168 or 169 pounds," Dunkin said. "He says he wants to be a super middleweight now. There's no way he can go back the other way [to 160]. He realized he is just too big."
When Moretti is in Puerto Rico for a news conference on Tuesday to formally announce featherweight titlist Juan Manuel Lopez's April 16 fight with Orlando Salido, he said he is going to meet with promoter Tuto Zabala Jr., who promotes Puerto Rican junior featherweight titlist Wilfredo Vazquez Jr. (20-0-1, 17 KOs).
Moretti said he and Zabala will try to close the deal that they have been working on to match Vazquez in a title defense against Mexico's Jorge Arce (56-6-2, 43 KOs), a former flyweight and junior bantamweight titlist. Part of that deal could be Top Rank coming aboard as Vazquez's co-promoter.
Dan Rafael covers boxing for ESPN.com. Follow him on Twitter.