The 31-year-old Texan was originally supposed to face Manny Pacquiao in August but the bout was cancelled after he suffered a detached retina a week before the fight.
Up stepped Ugas, who shocked the world by upsetting Pacquiao, sending the Philippines presidential candidate into something of a late retirement.
WBA president Gilberto Mendoza then gave his seal of approval for IBF and WBC welterweight titleholder Spence to challenge the Cuban for his shiny new belt.
As reported by BoxingScene.com, Ugas told Fox Sports: “We are targeting March or April for the fight. It’s a fight for three titles. It’s a fight that we want and are targeting the springtime.”
Spence said on his Instagram account: “The fight’s in April, man down, strap season. He already know what time it is.”
The fight is expected to take place in the United States, with Las Vegas or Los Angeles appearing the most likely destinations.
A win for either man could set up a world title fight against WBO welterweight champ Terence Crawford, who is now a free agent after parting ways with Top Rank.
Spence Jr’s all-American welterweight unification showdown with Crawford is one of the most-talked about fights in the history of the sport.
But Matchroom Boxing promoter Eddie Hearn believes Spence will purposefully move up to middleweight in order to avoid fighting Crawford.
Hearn, 42, told iFL TV: “Terence Crawford is a great fighter, but I just think it’s hard for Terence because I think he’s the best welterweight in the world.
“But at the same time, where are the fights that are going to generate the kind of money that he wants? Really, that’s Errol Spence.
“I think you’re going to see Errol Spence move up to 154 to avoid Terence Crawford. ‘Avoid’ is maybe a harsh word, but strategically avoid.”