By Edward Chaykovsky

Eddie Hearn, who promotes IBF welterweight champion Kell Brook (36-1, 25 KOs), expects everything to get finalized by next week for a mandatory defense against undefeated Olympian Errol Spence (21-0, 18 KOs).

The IBF had ordered a purse bid, which was scheduled to take place tomorrow, but Hearn requested a one week extension as both sides are close to reaching a deal. A deal was expected with Brook's side holding the edge if it went to a purse bid with a 75-25 split. The fight is practically a lock to take place in the UK.

The fight became likely after Hearn's attempts to finalize a domestic blockbuster with Amir Khan had fallen apart two weeks ago, after Khan insisted on a 70-30 split among other items.

Brook's last fight took place in the middleweight division, after he moved up by thirteen pounds to challenge IBO, IBF, WBA, WBC world champion Gennady Golovkin last September at the O2 Arena in London. Brook suffered a fractured orbital bone in the contest, which was finally stopped in the fifth round.

Hearn makes it no secret that he would rather have Brook drop the IBF title and make a move to the junior middleweight division - where it would be much easier to make the weight limit. The biggest problem with Brook fighting at 154, admits Hearn, is the lack of big  money opponents. All of the lucrative names are in the welterweight division.

Spence has been the mandatory challenger, waiting patiently, since last August, when he knocked out Leonard Bundu in spectacular fashion in Coney Island, Brooklyn.

According to Hearn, the only way a Spence deal will not get finalized is if Khan comes around and becomes more relaxed with his financial demands - which is not likely to happen.

Hearn told Sportsmail: "It’s no secret that it is a struggle for Kell to make 147 pounds and I felt he would be better off at 154. But Kell does not want to vacate. Spence is who he wants to fight and that fight is very close to being made.

"The only way we would not do it is if Khan comes about, but he wants a tune-up fight first. A fight with Spence is the firm favorite and I’d hope to make it in the next week."