DEONTAY WILDER and Otto Wallin were changed men after fighting Tyson Fury, claims his dad John.
The Gypsy King went the distance with both fighters, before fighting Wilder a further two times.
He faced Wilder for the first time in 2018 and survived a last-round knock-out to secure a draw, before going on to fight Wallin 10 months later.
Fury suffered a nasty cut over his right eyebrow following a clash of heads with Wallin but survived until the final bell, winning via unaminous decision.
He later fought Wilder twice, stopping the American in their rematch before knocking him out in their trilogy fight.
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Both boxers fought on the same card last month in Saudi Arabia with Wallin defeated in five rounds by Anthony Joshua, while Wilder lost to Joseph Parker, and John Fury feels neither boxer is the same fighter they were before fighting his son.
He told Seconds Out: “Otto Wallin was s*** scared of Anthony Joshua. Fair play to AJ, he looked like a man on a mission. Wallin never turned up, just like Deontay Wilder never [vs Joseph Parker].
"I've never seen anything as bad as Wilder in my life. I was looking at two different people in Wallin and Wilder - those were not the people who fought Tyson. Tyson probably took everything out of them.”
Fury, 35, is set to fight Oleksandr Usyk next in an undisputed heavyweight clash on February 17.
Last tine out Fury struggled to a points win over former UFC champion Francis Ngannou and his dad has warned he will need to alter his style for the challenge of Usyk.
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He said: “He needs a different style altogether with Usyk, he’s totally different.
“If you go back to, many years ago, you can watch it on the internet, it’s Gerry Cooney-Michael Spinks.
“Michael Spinks is a blown-up light-heavyweight weighing just over fourteen stone at the time.
“Gerry Cooney is six-foot-seven, eighteen stone, look what happened.
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“These are speed-men, you just can’t have that straight-up, going forward, looking to land a bomb on these kind of fighters because guess what?
“They can see it coming and they will avoid it.
“Usyk is very good, he is a good mover, he’s got a brain, he’s got good footwork and the style for Deontay Wilder and Francis Ngannou isn’t going to cut it for a man like Usyk.”
