Barry McGuigan says Carl Frampton has been making short work of his sparring partners as he prepares for his WBC super-bantamweight title final eliminator against Hugo Cazares in Belfast on 4 April.
"The things he is doing in training are extraordinary," McGuigan told BBC Sport Northern Ireland on Tuesday.
"He's knocking over sparring partners who are two stone heavier than him. We can't keep guys. They all want to leave after a couple of days."
McGuigan says victory for Frampton against two-time former world champion Cazares, 35, would set him up for a tilt at WBC champion Leo Santa Cruz in the late summer.
IBF champion Kiko Martinez turned down an offer from the Frampton camp and McGuigan says that the Spaniard is "petrified" of the Belfast man after losing a European title fight against him 14 months ago.