Dan McCarney had surgery last week

North Texas coach Dan McCarney underwent heart bypass surgery last Friday, sources told ESPN.

McCarney, 59, acknowledged in a statement that he had a medical procedure but wasn't specific. He returned to the office Friday, a week after the surgery. Doctors recommended McCarney undergo the surgery following a routine office visit earlier in the week.

"The medical staff was outstanding," McCarney said in a statement released through North Texas. "I put my future in their hands and everything went great. I have already begun the road to recovery and am excited to be back in the office working toward making the Mean Green football program better."

The heart procedure was not related to a stroke he had in February 2012, a source told ESPN.

Since arriving in 2011, McCarney (9-13 in two seasons) has turned around the Mean Green program. In the six years before his hiring, the Mean Green were the nation's losingest program, winning only 13 of 71 games.

In the past 50 years, only Rod Rust (1967-68) has won more games in his first two seasons at North Texas than McCarney has.