"It's not the pain. I feel like when I swing my belly button is going to go shooting at the pitcher," Dunn said Thursday as he sat in front of his locker.
"Seriously, that's what it feels like. Until that goes away where I can swing and not feel like that. ... My main goal was to try to play today. I wanted to be out there today. And if that's not going to happen, I want to get it to where it's not going to bother me."
Dunn, who signed a four-year, $56 million contract with Chicago as a free agent, initially began to feel some discomfort Sunday in Cleveland and it got worse Monday night in Kansas City during an off-day.
He's the second player this season to be sidelined by an appendectomy, joining the Cardinals' Matt Holliday, whose case turned out to be a point of reference for Dunn.
"It was kind of like a two-day buildup, and after the Matt Holliday stuff I was kind of laying in bed Monday night and when it was really kind of bothering me pretty bad, and I realized that this has the potential to be that," Dunn said.
"I didn't want to let that linger on too long. ... I knew something wasn't right. I knew it wasn't a muscle. I wanted to make sure the thing didn't blow up and we had a whole different problem."
Dunn played in the White Sox's 12-inning loss to the Royals on Tuesday night and then went to the hospital after the game. He had the surgery early Wednesday morning, a laparoscopic procedure that is less invasive.
He's been in a hurry to get back. In four games so far, he's batting .286 with a homer and five RBI.
"I appreciate when the guys want to play for you. But in the meanwhile, we have to be careful when you have a surgery, no matter how small it is. It's still dangerous," White Sox manager Ozzie Guillen said.
Dunn said there is no timetable for his return. He'd like to be back for Friday's game against the Rays.
"I feel like if I'm able to go out and perform and not hurt the team, I want to do it," he said, adding he wasn't going to miss being at the park for the opener -- even if he can't play.
"I can function, it's just sore and kind of tough to move around," he said. "I definitely wasn't going to stay at home, that's for sure."
The White Sox also announced they designated for assignment outfielder Lastings Milledge and purchased the contract of right-handed pitcher Jeff Gray from Triple-A Charlotte. Milledge, initially signed to a minor-league contract, was 1 for 4 in two games.
Gray is 1-1 with a 4.91 ERA in 36 major-league relief appearances with Oakland and the Cubs.