Eddie Hearn admits Timothy Bradley is the No 1 target for Kell Brook, with work already underway to make the fight.
IBF world welterweight champion Brook takes on Kevin Bizier on Saturday, live on Sky Sports, in a mandatory defence.
The Special One missed out on an Amir Khan showdown and is looking to take on a big name later this year and promoter Hearn is keeping his options open, but is hopeful a Bradley fight can be made after the American has fought Manny Pacquiao.
"The Bradley fight is one I've always thought could happen for Kell Brook," he told Sky Sports.
"I think he's one of the elite fighters in the world that would travel.
"There were talks with Top Rank a few years ago about making it but it would have been a voluntary defence with options, but Kell was the mandatory for the IBF world title at the time.
"I actually think Tim Bradley will beat Manny Pacquiao in which case maybe we'll have to travel ourselves to the States - which doesn't bother Kell or us in the slightest.
"Of course Bradley and Top Rank have got plenty going on but the calls never stop and there has been work behind the scenes for the last month about Kell Brook.
"Top Rank aren't going to make a decision and even if that is a great fight and Bradley loses and comes through that, it would still be a great fight for Kell Brook.
"Brook will be a keen spectator on April 9. And if Pacquiao wins it, we would walk to Timbuktu for that one."
While WBA champion Keith Thurman's defence against Brook victim Shawn Porter has been postponed until June, Hearn believes WBC holder Danny Garcia is "rumoured to be waiting" for a fight with Floyd Mayweather.
Jessie Vargas has recently won the WBO belt at 147lbs, but the promoter behind the Sheffield star wonders if the new champion is a big enough name at the moment.
Hearn is confident Brook could step up a division and take on the likes of Miguel Cotto and Gennady Golovkin, but made it clear a bout against Bradley and a campaign to be the world's best welterweight is the priority.
"The timing hasn't helped, but the one thing we do know is, if Kell beats Kevin Bizier, he needs a big fight," he said.
"Doors close through no fault of your own and you have to be creative and have to make a move - and that might be 154lbs but we want to clean up at welterweight.
"If we can't find the big fights at 147lbs, Kell does have the ability to move up to 154lbs, but he has worked so hard to win this belt and while he is still making the weight effectively, we'd like to clean up the welterweight division.
"We don't want to get held up by politics, or just because Kell Brook is very, very good and many of them don't want to fight him.
"If we have to move up to 154lbs we'd fight Cotto or even Gennady Golovkin at something like 157lbs, but here and now, we want to dominate the welterweight division."