Andre Agassi has told ESPN’s Rick Reilly that he feels "sick" about his confrontation with Pete Sampras at the Hit for Haiti on Friday.

"It was out of line," he said. "It was inappropriate. The night was on fire. We were all having fun. I was trying to be comedic. I only had a split second to make a decision. I went for it and it fell flat. I was trying to get past it, but Pete didn't really let me get past it. He didn't really roll with it. I've texted Pete to ask him if I can apologize in person."

Agassi said Sampras hasn't texted back. After imitating Sampras being a bad tipper, Agassi found his clearly-upset rival firing a serve past his head."I nearly lost it in the lights. It was close," said Agassi.

Agassi, who criticized Sampras on the same subject in his autobiography last year, added, "The joke fell flat and I'm sorry.

"My hope was that the night was still enjoyable. My whole book is about living and learning, and I guess you never frickin' stop."