Novak Djokovic got over his Wimbledon loss with some family time -- but the tennis superstar certainly wasn't taking it easy during daddy duty ... putting his athleticism to the test via some friendly competition against the little ones!!
38-year-old Joker hit the beach in Mykonos with his wife and children this week ... and he was clearly ready for anything as he ditched his shirt and rocked some short orange trunks for the occasion.
While some would expect the 24-time Grand Slam winner to relax a bit after falling in the semifinals against Jannik Sinner in London earlier this month, that certainly wasn't the case -- he was spotted taking part in some sprints and long jumps with the youngins as he caught some rays.