"As a pro what he has done is get an awful lot of rounds. Three of his world title fights have gone the 12 rounds and he had done 12 rounds before that. And some of them weren't easy, he had to think."
Meanwhile, British boxing legend Frank Bruno thinks Anthony Joshua should use his natural reach and power rather than go chasing a knockout against Parker.
Bruno is wary of Parker's threat and thinks Joshua would be better served trying to out-box his opponent.
"Anthony Joshua has got the size, the power, and the skill - and Parker is a guy who comes to him all the time," Bruno told Sky Sports.
"If Joshua moves around and uses his reach and his power, he should make it, not an easy fight, but make it easier for himself.
"Joshua has a lot of skill, a lot of size, a lot of power. If he just relaxes and uses Parker to come in, it is as simple as that."
"If he is going to get macho and start wanting to tear up with him, then Parker is a very dangerous guy, very fit, and he is on you all the time," Bruno added.