Fury has not fought since knocking out Deontay Wilder in February 2020, and Lee has said the time out of the ring could be a hindrance to the 32-year-old.
“He is frustrated. The end-date was February, then it was March, now we’re still going on,” Lee told Sky Sports.
“He’s very frustrated that the biggest, most powerful people in boxing can’t seem to get the deal done for whatever reason.
“It’s inevitable that it will happen, 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.”
Lee is a member of Fury’s corner but worked with Joshua Parker in the lead up to the heavyweight’s fight with Derrick Chisora in Manchester last week.
Fury has been training in Las Vegas, where he called Hearn an “absolute w****r” in an Instagram story post before claiming that he would beat Joshua within three rounds if the heavyweight unification fight does go ahead.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies