16-time world champion and WWE fan favorite Ric Flair is in the hospital with what one of his representatives call “some tough medical issues.”

Two-time WWE Hall of Famer Ric Flair remains in critical condition following surgery Monday, according to WWE during Tuesday night’s SmackDown Live broadcast.

Announcer Tom Phillips said Flair, 68, was “resting comfortably” in an Atlanta hospital.

Neither Flair’s representatives nor WWE has released the specifics of the surgery. Longtime wrestling announcer and close Flair friend, Gene Okerlund, has tweeted that Flair had colon surgery.

On Monday night, Melinda Morris Zanoni, CEO of Legacy Talent and Entertainment, tweeted there was “still a long road ahead” and urged supporters to keep Flair, his three children and fiance in their prayers. She did not provide an update Tuesday and has said that she cannot answer any personal questions.

In the first comments from the Flair family, daughter Ashley (who wrestles for WWE as Charlotte) took to Instagram: “Hi guys, On behalf of my family and I, we want to THANK everyone for the prayers, texts, calls and support. Our Dad is a FIGHTER and your continued thoughts and prayers MEAN THE WORLD to us. We will update everyone when we have more information.”

Flair was reportedly put in a medically induced coma earlier Monday in advance of the surgery.

Morris Zanoni had initially downplayed Flair’s hospitalization Saturday for what was described as “routine monitoring.”

The situation, however, escalated quickly and she tweeted late Sunday night asking for prayers for Flair, saying that he was facing “some tough medical issues.”