0733 GMT February 25, 2020
The Briton, who defended his IBF title against Eric Molina on Saturday, is set to meet ex-champion Klitschko in April, BBC reported.
Joshua, 27, has recently begun working fulltime again with McCracken, who trained him as an amateur, helping him win Olympic gold at London 2012.
"Without a doubt, he can knock anybody out," McCracken told BBC Radio 5 live.
"If he hits them hard enough, he will without a doubt knock them out.
"Anthony can box, can move well, has great balance. Speed is the key as well.
"When you have his speed, they don't see the punches coming. And that will be the plan for Klitschko, that he just can't avoid or defend what's coming from Anthony.
"He's looking forward to it. He's enjoying his boxing. The tests lie ahead but he's in a great place and we're more than confident that he'll beat Klitschko."
McCracken watched at Manchester Arena on Saturday as the Watford-born fighter stopped American Molina in the third round.
Promoter Eddie Hearn then announced that Joshua would fight Klitschko at Wembley Arena on 29 April, by which time the Ukrainian will be 41.
"Klitschko is a different type of test," McCracken said. "Klitschko won't be fazed — he's hugely experienced.
"He knows his way around, he knows how to jab and grab and nullify big punchers. He's beaten big punchers before, but I think Anthony's more than a big puncher."
Klitschko became free to fight Joshua for the WBA and IBF belts after Tyson Fury relinquished his titles in October.
Britain's Fury, who beat Klitschko to win the WBA and WBO titles in November 2015, had twice pulled out of scheduled rematches.