Tennis legend Bjorn Borg has revealed that he was diagnosed with an "extremely aggressive” prostate cancer, a battle he says is now in remission after surgery earlier this year.

The 69-year-old Swede discloses the illness in the closing chapter of his forthcoming autobiography, Heartbeats, which he co-wrote with his wife, Patricia.

The book, due out Sept. 18 in Britain and Sept. 23 in the U.S., pulls back the curtain on one of sport’s most famously private champions.

"I have nothing right now. But every six months I have to go and check myself,” Borg said in a video interview from his home in Stockholm. "The whole process, it’s not a fun thing. But I’m OK. I’m fine. And I’m feeling very good.”

Borg said doctors first raised concerns in September 2023, just as he was set to captain Team Europe at the Laver Cup in Vancouver. Against medical advice, he made the trip. "Of course I went ... I didn’t listen,” he admitted. Upon returning to Sweden, tests confirmed the cancer diagnosis.

Surgery was scheduled for February 2024, a wait Borg described as "psychologically very difficult, because who knows what’s going to happen?” His most recent scans, taken in August, came back clean.

In the memoir, Borg reflects on the diagnosis with the same resolve that defined his playing career: "Now I have a new opponent in cancer – one I can’t control. But I’m going to beat it. I’m not giving up. I fight like every day is a Wimbledon final. And those usually go pretty well, don’t they?”

The 11-time Grand Slam champion – six French Opens between 1974 and 1981, five consecutive Wimbledons from 1976 to 1980 – shocked the tennis world by retiring at just 26 in 1983. He made a brief, unsuccessful comeback in 1991, still wielding a wooden racket.

Beyond his on-court triumphs, Heartbeats revisits Borg’s turbulent personal journey, from struggles with drugs to relationships with women and family. Writing it, he said, was a "relief.”

"I went through some difficult times, but to do this book ... I feel so much better,” Borg said.