Tyson Fury is given “hell” in his training camp by Jared Anderson, who has been named as the heavyweight division's eventual king by promoter Bob Arum.
Fury will defend his WBC championship in a trilogy fight against Deontay Wilder in Las Vegas on July 24 and has again recruited the talented Anderson as a sparring partner.
Anderson, an unbeaten 21-year-old American, was a key aide in Fury's previous preparation to defeat Wilder.
"We have a guy who Tyson tells me, and a lot of people tell me, will be the next great heavyweight champion," Top Rank promoter Arum told Sky Sports about Anderson.
"The kid has had nine fights now.
"Talk to Tyson - he gives Tyson hell when they work out. He's a great sparring partner.
"Tyson said to me after the Wilder fight that he attributes a great deal of his success to sparring with Anderson."
Anderson has a 100 percent knockout ratio from his pro career so far including a highlight reel stoppage of Kingsley Ibeh which perfectly demonstrated his reflexes and power in one lightning-quick fight-ending combination.
His elusiveness is why Fury has recruited him as a sparring partner.
"If you can hit me, then you've got some speed and technique," Anderson told Sky Sports after his first experience in camp wth Fury.
"He knew that if he could hit me, he could definitely hit Wilder."
Anderson described his style: "Elusive, quick, sharp. I am not the biggest or strongest but I'm always in front of you, throwing punches."
The WBC champion's father John Fury insists his son will never lose - but tipped Anderson to eventually succeed him.
"They aren't going to beat him," John Fury said about his son. "You can see the crop of heavyweights - they are all good, but not in Tyson's class.
"Tyson is out there on his own. Unless there is a fighter born, who comes out of nowhere with an amazing talent, but I've not seen him yet.
"There's one - Jared Anderson. He's an unbeaten heavyweight with [promoter] Bob Arum.
"I do believe he can be the next big thing when Tyson is gone.
"But the kid is only 21 years old. He's got a bit to do yet.
"He's the only one who stands out for me. All these other guys? They are all on the same par."
Anderson will feature on the Fury vs Wilder undercard against Vladimir Tereshkin.
Efe Ajagba, another Top Rank promoted heavyweight contender, has also been sparring Fury in preparation for his own fight against Cuban rival Frank Sanchez on the same bill.
Robert Helenius and Adam Kownacki, two other highly-ranked heavyweights, will have a rematch on the Las Vegas show.