Kell Brook has piled the pressure on Amir Khan after arranging his IBF welterweight title defence on the same night as his bitter rival's fight in May.
Brook, 28, stopped Jo Jo Dan just nine days ago to make his first defence of the world title and was not expected to box again until late in the summer.
However, Khan's intention to fight Chris Algieri in New York on May 30, rather than accept Brook's offer of a bout at Wembley Stadium, has seen Brook arrange a fight against Frankie Gavin on the same night at the O2 Arena in London.
Khan, also 28, played down Brook's chances of earning a money-spinning fight, labelling Brook an "unknown".
"No one in America knows who Kell Brook is, whereas I can't walk the street without it getting crazy," Khan told Fighthype. "Everyone knows who Amir Khan is but it's a nice thing.
"I've seen his [Brook's] performance against Jo Jo Dan and he's going on like beating Jo Jo Dan is like beating a five-time world champion."
Brook responded with frustration, claiming he could not understand why Khan refused to fight him.
"If someone said to me you can get five million quid, a world title, fight at Wembley with a fight that every fan wants to see, it's a no-brainer for me," Brook told the BBC.
"He's fighting Algieri who didn't win a round against [Manny] Pacquiao, a feather puncher, not a big puncher. It doesn't make sense to me. I'm world champion, I'm calling him out, we want the fight, there's a world title and a bagful of money and it doesn't make sense that he's fighting this guy who's bringing nothing to the table."
As a result of his fight against Gavin, Brook will have to turn down Sky's enticing offer to commentate on Floyd Mayweather's monumental clash against Manny Pacquiao in Las Vegas.
However, Brook has clearly decided that the positives outweigh the negatives. If he beats Gavin, Brook could defend his title again as soon as July, with talks between his and Brandon Rios' camps in progress for what would be a greatly anticipated fight.
But first, Brook must overcome the considerable challenge of Gavin, the only British boxer to win a world amateur gold medal. Not even Anthony Joshua, who secured his 11th professional victory last night, can match that. Joshua, 25, could only manage a silver before he turned pro.