Wladimir Klitschko poked fun at Tony Thompson on the eve of their world heavyweight title clash in Switzerland on Saturday.
Klitschko defeated the American four years ago, stopping him in the 11th round after taking longer than normal to take out his opponent.
Thompson offered little in the way of offense on that occasion, afterwards blaming his performance on a knee injury.
The Ukrainian champion brought the issue up at the pre-fight press conference as he looks to extend his winning streak to 16.
"We sat here four years ago and you said you were going to beat me, you told me that you were going to knock me out," Klitschko said.
"You were very confident going in to the fight but you lost and after you said you were injured.
"I don't understand why you only said you had the injury after the fight..."
Klitschko has been accused of opting for easier fights in the past but he had no other option than to take on Thompson again because he is the IBF mandatory challenger.
"I had no choice (but to fight Thompson)," Klitschko added. "I have to defend my titles, but to fight Tony Thompson is definitely not an easy job. It's not going to be a vacation fight for me."