WBC lightweight champion Devin Haney has indicated that Teofimo Lopez must face him in order to establish "who the real king is" at 135-pounds.
In a recent interview, Lopez expressed his desire to face Haney before the end of the year.
The next assignment for Lopez, who holds the IBF, WBC Franchise, WBA, WBO titles, is a likely mandatory title defense against George Kambosos, which is currently heading to a purse bid.
Haney does not believe Lopez is serious about his intentions to come together for a fight.
"This guy is a liar. Watch his interviews. He says one thing in one interview, then says a different thing in a different interview. One day he's going to send me and [his mandatory challenger] George Kambosos Jr. a contract to see who signs it first. One day he's going to save my career. One day this, one day that. His lies don't add up," Haney told Sky Sports.
There are several lucrative options for Haney at lightweight - with undefeated stars like Ryan Garcia and Gervonta 'Tank' Davis.
Garcia holds the WBC's interim-title at the weight, while Davis is the WBA's "regular" champion.
But, Haney's preferred opponent is Lopez, who last year shocked the sport when he secured an upset unanimous decision over Vasiliy Lomachenko.
"Because I want all of the belts. We need to know who the real king is at 135lbs is. Who is the real undisputed champion? The only way to settle that is for us to fight. I see Teofimo as the No 1 threat then 'Tank' Davis. I feel like 'Tank' is really a 130-pound fighter. He had trouble with Yuriorkis Gamboa moving up in weight - he is a lot smaller than the other guys at 135-pounds," Haney said.