"Eight operations since we started American Idol... He's hitting 50 percent, but he's still up there swinging away," the elder Phillips told People following Wednesday night's Idol finale broadcast in which his son was crowned champion.
"He's been doing [well], but it's just grueling hours and it's just amazing what he's done through the journey."
Phillips Sr. said American Idol viewers didn't even get to see his son's full potential in the competition because he was constantly feeling under the weather.
"They've just seen a glimpse of what Phillip can do. We can't wait to get him well and 100 percent and really see how he can perform," Phillips' father explained, adding he was so proud of his son's Idol victory he could cry.
Phillips reportedly underwent all the operations to remove a build-up of kidney stones, and the 21-year-old pawn shop worker from Leesburg, GA, is anticipating going under the knife again soon to repair his failing right kidney.
"The recovery's probably two to four weeks," the singer's father told People. "He's healthy, he's good. His kidneys are good. I can't wait for America and the whole world to see him [after his surgery], because he's a big cut-up. He's going to have some fun."