Ali Abdelaziz, who represents Khabib, Justin Gaethje and other top fighters, discussed McGregor's current status with TMZ Sports.
"Right now, he's on punishment for his bad behavior," Abdelaziz said. "Right now, he needs to sit down. Go fight Tony Ferguson, stay busy, stay active. Go fight [Jorge] Masvidal. Stay active, I want to see activity. Remember, he used to say that to all of us. Guess what? Payback is a b---h."
Abdelaziz also clearly doesn't believe the retirement announcement is real.
"Same old prostitute; he wants attention," the manager told TMZ.
McGregor, 31, recently explained that his lack of quality opportunities led to his third retirement announcement in four years.
"All this waiting around. There's nothing happening," he told Ariel Helwani of ESPN. "I'm going through opponent options, and there's nothing really there at the minute. There's nothing that's exciting me."
The Irish star defeated Donald Cerrone in January at UFC 246, but UFC President Dana White said McGregor turned down the opportunity to be a replacement at UFC 249 in May.
Gaethje replaced Nurmagomedov, who was unable to compete because of travel bans, and won the interim lightweight title by defeating Tony Ferguson via TKO in Round 5.
The next title fight in the division will be a unification bout between Khabib and Gaethje, reportedly set for September, per Adam Guillen Jr. of MMA Fighting.
McGregor, the No. 4 contender in the latest UFC lightweight rankings, would have to wait at least until that bout is settled before he could set up a title fight.