If you thought Roger Federer continues to play tennis in his spare time, you assumed wrong.

Federer called time on a legendary 24-year career in tennis last September after announcing his retirement due to ongoing knee issues at the time.

It's been nearly a year since and while his knee has healed up quite a bit, he still remains unable to play tennis during retirement. But it has nothing to do with age for the 42-year-old — instead, he struggles to find anyone to play with so he mostly ends up playing with his kids.

“I don’t play much tennis anymore, other than with the kids,” Federer told the Wall Street Journal. “As a former player, to book a court and get someone to hit with you is a process, so you end up not doing it.

“On vacation, I just played with our friends in the Hamptons. I’m not super competitive. It’s just nice to be out there and then sit on the terrace and let the sweat go a bit.”

We may potentially get Federers playing professional tennis again soon as the Swiss legend revealed his 14-year-old twin daughters Myla Rose and Charlene Riva are now fans of the sport despite initially being uninterested.

In fact, they were training at the John McEnroe Academy while his boys were at the Rafael Nadal Academy in Mallorca, Spain.

“All four kids love it,” he added, “The girls didn’t love it in the beginning but as they get better, they’re enjoying it and playing points now. They were up at [John] McEnroe Academy in East Hampton, and the boys were in Mallorca at the [Nadal] camp for a couple of days.”

Federer, himself, even takes part in the coaching when he has time.

“When I have time — and I try to make the time — I go on the court with them and try to teach them a little bit,” Federer explained. “It’s obviously an interesting dynamic, because I’m the dad, and not a former player. It is what it is [laughing].”

Federer is set to return to the court for the Laver Cup later this month in Vancouver, Canada. But rather than playing, he will be honored at the event while taking part in a special Q&A.