"Joseph is 24 years of age and by the time he fights Anthony Joshua, he will have had 20, maybe 21 fights. Breazeale hasn't exactly been active since he became a professional, so his skill set was incredibly limited.
"He did show he's got a hell of a chin, but he didn't offer much for Anthony Joshua to be worried about at all. But Joshua showed a lot to us that makes us very confident going into this fight.
"How is AJ going to go when he's eating Joseph's jab all night?"
Joshua is not expected to return to the ring until the end of the year, but Lonergan revealed Parker is aiming for a November bout.
"We're ready now. If Eddie Hearn rang me up tomorrow and says we want to fight in the mandatory period, we want to fight November or December - that would be fantastic," said Lonergan.
"We'll probably fight in late September, early October, and then the mandatory period comes up November 19. Any day after that, Joseph would be ready."