WATCH: Federer's son Lenny steals all of Ljubicic's attention

Being a coach on Team Roger Federer is a difficult job—not only because you're responsible for the career of one of the greatest players of all time, but also because, Federer being the father of two sets of twins, there are often children in his player's box.

But coach Ivan Ljubicic, it seems, handles both of those challenges exceptionally well. Note how he embraces the poking of Federer's son four-year-old Lenny:

"Back in the day, you know, it was playing in front of your parents, then it's [playing] in front of your friends that's special, then it's famous people, musicians," Federer told Jim Courier after his three-set third-round win over Taylor Fritz.

"At the end, it's back to basics, and it's playing in front of your family ... So for me it was a very special match, and I'm happy Lenny was there in the first set today."

Federer's name also came up in the post-match interview of Sloane Stephens, who, by the Australian Open's count, recorded her 200th career win on Friday by beating Petra Martic to reach the round of 16.

"Nothing compared to like Roger. I know he has like 12,000 wins," Stephens said.

While 12,000 might have hyperbole, it wasn't bad at all for an off-the-cuff answer; the Swiss is actually nearing 1,200, with 1,183 currently.

He'll be going for No. 1,184 next, against Stefanos Tsitsipas. Stephens, in her fourth-round match, plays Anastasia Pavlyuchenkova.