Five years ago, Lindsey Vonn retired from ski racing, largely because her aching right knee, damaged by high speed crashes and multiple surgeries, could no longer take the stress of the sport.

“My career ended with no intention of coming back,” Vonn, the winner of three Winter Olympic medals and 82 World Cup races, said in an interview last week. But seven months ago, Vonn had right-knee replacement surgery. Ten weeks later, she resumed skiing and was startled to be pain-free.

“I had a smile so wide it was coming through the back of my helmet,” Vonn said.In a turn of events that Vonn, 40, called “amazing and definitely not planned,” she will rejoin the United States ski team Friday with hopes of racing on the World Cup circuit this winter, perhaps as soon as next month. Vonn, who has privately logged 15 days of on-snow race training in Europe and New Zealand since August, said she would participate in the U.S. ski team’s training sessions at Copper Mountain in Colorado that begin Saturday, focusing on the speed disciplines of super-G and downhill.

Vonn is trying to join a growing list of professional athletes — including NFL quarterback Tom Brady, who won a Super Bowl at 43; Serena Williams, who left tennis just days before her 41st birthday with 23 Grand Slam titles; and Tiger Woods, who won the Masters Tournament at 43 — who extended their careers into their 40s.

“I’m trying not to get too far ahead of myself because I have quite a few hoops to jump through,” Vonn said. She added: “Obviously, I wouldn’t be doing this if I didn’t hope to be racing. I have aspirations. I love to go fast. How fast can I go? I don’t know.

“But I’m not going to put myself in a position to fail. My goal is to enjoy this, and hopefully that road takes me to World Cup races. I wouldn’t be back on the U.S. ski team if I didn’t have intentions.”

Returning to the Olympic Games for a fifth time could be part of Vonn’s future in 15 months. The Alpine races of the 2026 Winter Olympics will be held in Cortina d’Ampezzo, Italy, where Vonn won 12 World Cup races from 2008-18.