Andy Lee, who is part of the Tyson Fury's training team, says the WBC heavyweight champion is not very happy with the increased delay in finalizing the fight with IBF, IBO, WBA, WBO champion Anthony Joshua.
The two sides are currently reviewing the contracts for the site fee agreement, with the contest targeted to take place in late July or August. A group in Saudi Arabia has offered a reported $150 million to stage the event.
Fury has been out of the ring since February of 2020, when he stopped Deontay Wilder in seven rounds to capture the WBC world title.
The 'Gypsy King' is currently in Las Vegas, training with Lee and head trainer Sugarhill Steward.
Fury is very eager to return to the ring sooner than later and he's becoming agitated with being inactive for such a long period of time.
"He is frustrated," Lee told Sky Sports about Fury. "The end-date was February, then it was March, now we're still going on.
"He's very frustrated that the biggest, most powerful people in boxing (promoters Bob Arum, Eddie Hearn and all the networks) but they can't seem to get the deal done for whatever reason."
According to Lee, Fury could have fought in February or March - but his next fight has been held back while the respective teams of both champions continue to negotiate.
"It's inevitable that it will happen," Lee said.
"But all this sitting around and waiting? Tyson could have fought in February or March. He's been held up by it. He does like to be active.
"I don't know if it's to his detriment or his benefit that this wait has happened. He will be ready to unleash the fury when this fight is on!"