Eight years after storming the U.S. Open quarterfinals as an unseeded teenager from Marietta, Melanie Oudin is retired from the sport.

Oudin’s career stalled following various health problems. She was diagnosed with a muscle condition (rhabdomyolysis) in 2013, and in 2014 experienced episodes of accelerated heartbeat on the court.

In a series of social media posts Friday, Oudin, 25, explained her recovery from the conditions had “taken a toll” and led to her decision to leave professional tennis.

Her statement in part reads:

“Unfortunately, since the end of 2012, I have been struck with numerous health issues and injuries. I would work so hard to come back after being, and then something else would happen.

“Competing with the best in the world requires your absolute best and without being 100 percent mentally and physically it is very difficult.”

In 2009 Oudin became the youngest quarterfinalist at the U.S. Open since Serena Williams, upsetting the likes of Maria Sharapova and Elen Dementieva.

Oudin won the AEGON Classic Tennis Tournament 2012, and a U.S. Open mixed doubles championship in 2011 with partner Jack Sock.

She was ranked as high as 31st in the world.

“I am sad to leave the sport I know and love,” Oudin wrote, “but I am very optimistic about what the future holds for me.”

The U.S. Open starts this week at Flushing Meadows in New York.