New dad Novak Djokovic has been taking advice from Roger Federer on balancing fatherhood with a tennis career.
Djokovic's wife Jelena gave birth to their first child, Stefan, last month.
The Serb returned to action last week with victory at the Paris Masters,where he sought the advice of father-of-four Federer.
"We spoke in Paris and he was one of the first players that congratulated me and wished me all the best," said world number one Djokovic.
"Of course he can identify with what I'm going through - I'm still far off from him, he has four kids, and it's pretty amazing to still play at such a high level with four kids.
"I understand what an effort it is with one; with four I can't imagine.
"We talked in Paris about certain things that involve travelling and so forth. He advised me and I will take it into account and hopefully I can organise my life as well as he did."
Djokovic, 27, won Wimbledon in July before getting married later that month, and is hoping to cap a special year with a third straight title at the ATP World Tour Finals, which get under way in London on Sunday.
He will play Marin Cilic in his opening match on Monday, with Tomas Berdych and Stan Wawrinka also in Group A.
"I won Paris without dropping a set - we should make more kids I guess!" he joked.
"I'm in a good place, fighting for number one in the world and in a good position," he added.
"I won this tournament twice in a row and it gives me enough reason to believe I can do well this year."
Asked how he deals with juggling family and professional demands, Federer said: "It really depends on the schedule of my matches.
"It's about deciding with [his wife] Mirka what's best for them and I kind of blend in, especially when I'm playing every day.
"I'm very busy, very active and I try to balance it as well as I can."
Federer, 33, could still overtake Djokovic for the end-of-year number one ranking and he begins his Group B campaign against Milos Raonic, having lost to the Canadian in Paris last week.
"I lost because he played well and I can accept that," said the Swiss.
"It's definitely more up to me than up to him, potentially. As I'm feeling good I'm actually happy I have the chance for a rematch."