After Billy Joe Saunders outpointed Andy Lee to claim a middleweight belt on Dec. 19, Tom Loeffler of K2 Promotions, which promotes unified titleholder Gennady Golovkin, made an offer to Saunders promoter Frank Warren to do a unification fight in the spring.

While the sides are talking about the fight, Loeffler is also making alternative plans in case a fight with Saunders doesn't get made (and it's a long shot anyway).

So there are also talks going on between Loeffler and Golden Boy Promotions for Golovkin's mandatory defense against Tureano Johnson, Golden Boy vice president Eric Gomez told ESPN.com.

The date they are discussing is April 23 (HBO) at Madison Square Garden in New York, Gomez said.

"We've had preliminary talks," Gomez said. "It's GGG's mandatory fight and it's a fight we'd like to make."

Loeffler confirmed that they are in discussions.

If Golovkin can land a unification fight, he would be granted an exception to the mandatory defense. Barring that, the mandatory challenger would likely be his next opponent.

Golovkin (34-0, 31 KOs) drew a sellout crowd of 20,548 (including presidential candidate Donald Trump) to Madison Square Garden for his Oct. 17 unification fight with David Lemieux -- another Golden Boy fighter -- whom he knocked out in the eighth round of a one-sided fight in his HBO PPV debut. Golovkin retained his title for the 15th time and notched his 21st knockout in a row.

On the undercard that night, Johnson (19-1, 13 KOs) knocked down Eamonn O'Kane twice in the first round and cruised to a lopsided unanimous decision in the title elimination fight that secured the mandatory title shot.

If Golovkin wins the April fight and middleweight champion Canelo Alvarez retains the title on May 7 (HBO PPV) against an opponent to be determined, the plan is for Alvarez and Golovkin to meet in September in what would be the biggest fight in boxing at the moment.