Caroline Wozniacki's not sweating missing out on one of the biggest days in women's tennis ... she's staying cool in the pool instead.
The tennis star and her NBA fiance, David Lee, are still vacationing in Italy -- now they're in Portofino -- and were spotted Saturday getting wet and enjoying some delicious-looking drinks.
As we reported ... the couple jetted over to Italy early this week after Caroline got bounced from Wimbledon in the second round.
So, she wasn't in attendance like Kate Middleton and Meghan Markle to watch Serena Williams go for her 24th Grand Slam title .