Eubank Jr called out Brook in the wake of his brilliant stoppage win in the grudge match against Amir Khan.

Brook is a former world welterweight (147lbs) champion who beat Khan at a 149lbs catchweight, but Eubank Jr operates at middleweight (160lbs) so a weight disparity is a problem in agreeing terms to fight.

"The fight is very realistic, but only if they are both realistic about the weight," promoter Ben Shalom said.

"Brook is happy to be realistic by coming up from 149lbs to 154lbs or 155lbs.

"But Eubank Jr also has to be realistic. And that involves coming down to 155lbs."

The rivalry between them started in 2016 when Eubank Jr was in talks to fight Gennadiy Golovkin.

Brook eventually took the fight with Golovkin instead - he bravely moved up two divisions to middleweight but lost by stoppage and suffered a broken eye socket.

"Brook made a mistake with Golovkin and won't make the same mistake again at this stage of his career," Shalom said.

"He has shown that he is willing to come up again to fight Eubank Jr.

"But Eubank Jr must come down in weight. If he can, it's a huge fight."

Conor Benn has also emerged as an option for Brook in his natural welterweight division.

"Brook has a lot of options now," Shalom said. "He has just won a huge event with a huge amount of interest in it.

"He showed himself to still be in a very good condition.

"Eubank Jr has fought for world titles, Benn hasn't. Eubank Jr is a bigger name. So you could argue that there is more in it for Brook."

'There's definitely a bit of needle there!'

Nisse Sauerland of Wasserman Boxing, who promote Eubank Jr, hopes a compromise can be reached over the weight limit for a grudge fight with Brook.

But Eubank Jr is also open to fighting world champions such as Golovkin or British rival Billy Joe Saunders after his recent win over Liam Williams.

"If you look at what Kell is saying, the five pounds to come up to 160, is not the be all and end all," Sauerland told Sky Sports.

"It sounds like a bit of an excuse. I think five pounds isn't the biggest of deals, but I'm sure there is a discussion to be had. But I can't see [Eubank] Junior going down to 155, unless he chops an arm off.

"Obviously Kell Brook is a massive fight, there's definitely a bit of needle started there as well. But of course, there's also Golovkin-Murata. We'll be looking very closely at the winner of that.

"We're also monitoring [Zhanibek] Alimkhanuly, the WBO route. You've got [Jermall] Charlo, the Billy Joe [Saunders] fight, which would be absolutely huge and a few other options that we're looking at as well."

Brook's last fight?

Shalom says Brook will make a final decision on his future, which could even lead to retirement.

"It's up to Kell. If he retires now he retires in a very, very happy place and I expect him to be considering that option," he said.

"But then again you have the likes of Chris Eubank Jr, Danny Garcia, Keith Thurman, Conor Benn all calling him out because he's the money fight now.

"He's sold out arenas all around the country, he's the biggest name at 147[lbs] in the UK right now that's available for the fight. Whether at 147 or if he goes up to 155 to fight Chris Eubank Jr, he's got big options.

"But again it's up to him and he'll take time with his family. Maybe we do see the retirement of a legend of the sport."