Former Wimbledon champion Marion Bartoli says she can "still compete with the best in the world" as she prepares to return to the WTA tour.
The Frenchwoman said she would not play events until she is "fully ready" but "can't wait" to return.
"I think at 33 you can still perform on the tennis court for quite some time," Bartoli told BBC World Service Sport.
"I think Serena and Venus Williams are the perfect example.
"Venus has been able to play two Grand Slam finals this year, Serena is coming back next year and I think they both say they want to play up until the Olympics in Tokyo in 2020 so I think I'm definitely not too old for that."
Venus, the older of the Williams sisters at 37, is currently ranked fifth in the world, 15 years after she reached a career-high of number one. She played in this year's WTA Finals for the first time since 2010, losing in the final to Caroline Wozniacki, and topped the prize money list for the year.
'I can't compare myself to Clijsters'
Bartoli defeated Germany's Sabine Lisicki to win her sole Grand Slam title at Wimbledon in 2013, but quit the sport less than six weeks later, citing persistent injury problems.
She said she had spoken to former world number one Kim Clijsters before announcing her comeback.
Clijsters retired from tennis in 2007 but won two US Opens (2009 and 2010) and an Australian Open (2011) after returning to the sport.
"I spoke to Kim quite a bit about it because obviously when she came back she was able to win Grand Slams," said Bartoli.
"I obviously can't compare myself to Kim, she has been a much better player than myself and she was physically a lot more gifted.
"She explained to me that the process is very important and I very much feel that way as well.
"I love also spending time in the gym every day to get fitter, stronger and faster. I know I have a long way to go but I'm very excited about it.
"Of course I won't play the same schedule when I was 18 or 20 years of age when I used to play 25-30 events a year."
Bartoli also confirmed that she would continue to work on other projects alongside her tennis career.
"I will still do some commentary work even though I'll be playing and of course I'll do my fashion.
"I'll be able to play with my own tennis line when back on the court which I'm very excited about and proud of."