'Time to say goodbye': Tennis star's sudden retirement at 31

German tennis player Julia Goerges is pictured shaking hands with Serena Williams after their match at Wimbledon in 2018.
German tennis player Julia Goerges has announced she will retire from the sport at the age of 31, ending a career that peaked with a semi-final appearance at Wimbledon in 2018. (Photo credit should read NEIL HALL/AFP via Getty Images)

Germany's former Wimbledon semi-finalist Julia Goerges has announced her retirement from tennis at the age of 31.

The Women's Tennis Association was quick to pay tribute on Wednesday to the power-serving German, who won seven tour titles during her career and made it into the game's top 10.

WOW: Stunning truth about Serena and Sharapova's millions

‘THIRD WHEEL’: Federer and Nadal's massive snub of rival

“Julia's powerful playing style, exemplary sportsmanship and thoughtful nature made her a fantastic ambassador for women's tennis and a fan favourite around the world," said Steve Simon, chief executive of the WTA.

Goerges reached her highest ranking of ninth in 2018 and is still ranked 45th as she quits the game.

In a letter addressed to the game of tennis, Goerges wrote that she was “ready to say ‘goodbye’” after a 15-year pro career.

“I always knew how I would feel when it is time to say goodbye to you, and that moment has arrived,” she said.

“I am ready to close the tennis chapter of my life and open a new one, which I am really excited about.”

Goerges reached the Wimbledon semi-finals in 2018, losing in straight sets to Serena Williams.

She was runner-up in the mixed doubles at the French Open in 2014 alongside Nenad Zimonjic and was a finalist in the Fed Cup with Germany in 2014.

Tennis players and fans were left stunned by the sudden announcement.

Tennis world erupts over Roger Federer announcement

Meanwhile, Roger Federer has delighted fans after announcing he’s on track to make his return to tennis at the Australian Open in January.

The 20-time grand slam champ says he is practising pain-free after undergoing two knee surgeries this year and says he expects to return to the circuit at Melbourne Park in January.

The 39-year-old Swiss reached the Australian Open semi-finals at the start of the year, but missed the rest of the season after undergoing a second arthroscopic procedure on his right knee.

Roger Federer is pictured during a press conference.
Roger Federer has announced he will likely compete at the Australian Open next year as his recovery from knee surgery continues. (Photo by Fabrice COFFRINI / AFP) (Photo by FABRICE COFFRINI/AFP via Getty Images)

“I'm on the right track,” Federer told German-language magazine Schweizer Illustrierte on Wednesday.

“I'm gradually coming back but I’m going to take my time and don’t want to put any pressure on myself.

“I will only take part in a tournament when I am 100 per cent fit.

“At the moment, it looks like I can make my comeback at the Australian Open in January.”

With Yahoo Sport Australia

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.