Juan Manuel Marquez's defeat to Manny Pacquiao on Saturday keeps alive the possibility of a fight with WBO interim lightweight champion Ricky Burns.
Marquez is the holder of the full WBO title at Burns's weight but had moved up to welterweight to take on the legendary Filipino in Las Vegas.
His controversial loss makes it less likely he will vacate his lightweight belt but could mean a date with Burns.
He had relinquished his WBO super-featherweight title to move up a weight class to the 9st 9lb mark.
On Sunday Burns's trainer Billy Nelson told BBC Scotland: "We would love to fight Marquez but it all depends on what he wants to do.
"He might go for a re-match with Pacquiao, he might retire or he might decide to drop back down to lightweight and defend his title.
"If he does defend his belt, then he has to fight Ricky because he has the interim title and is the mandatory challenger."
Nelson is still buoyed by Burns's impressive win over the Australian Katsidis at Wembley eight days ago, satisfied that "the game plan worked to a T" and particularly pleased by the way his boxer controlled the centre of the ring when he opted to.
And Burns's maturity and quiet confidence at the elite level of the sport means he and trainer Nelson would face Marquez with a belief they could take the full title, with any bout likely to be staged in the United States.
Nelson, who runs The Fighting Scots gym, added: "We wouldn't be thinking we'd made it just by getting a bout with Marquez; we'd be there to win it.
"We are very positive about the whole thing."
Nelson will have four boxers on the undercard when Glasgow's Willie Limond takes on Anthony Crolla for the Manchester fighter's British lightweight title in Motherwell on 25 November.
However, he did not think it likely that Burns and Limond would go toe to toe in the ring.
"That would be more of a domestic bout. We want Ricky to be fighting for world titles," said the coach.
"Willie would need to get himself up there in the WBO rankings to fight Ricky. He would need to beat Anthony Crolla and that will be no easy task."
At the MGM Grand arena, challenger Marquez, now 38, lost out to Pacquiao on a controversial majority decision, with two judges voting in favour of the reigning champion and the third scoring a tie.
Pacquiao, 32, has now won his last 15 bouts, but for Mexico's Marquez the decision was painfully reminiscent of his defeat to the same fighter in 2008. The pair also drew a contest in May 2004.
Marquez said after the bout: "This was the second robbery and this one was the worst. We won with clearer punches.
"It's hard when you're fighting your rival and the three judges too."
Marquez has won world titles at three weight divisions.
Last year he complained that progression to welterweight was accompanied by a loss of speed.
The coming weeks will reveal whether the ageing star opts to drop from his 142lb for the Pacquiao fight to extend his legacy in the 135lb lightweight category where a hungry Scot awaits.