When two tennis legends get together for lunch in LA, here's what happens ... they bring their own water!

In what appears to be a celebrity trend of bringing your own food to restaurants, tennis great Andre Agassi brought his own jug of alkaline water to Il Pastaoi in Beverly Hills as famously vegan with occasional pescatarian tendencies, scarfed down one the the Italian cafe's famous salads.

The backstory here is that Agassi is trying to revamp Djoko's career after a year full of injuries, hoping he'll skyrocket back to success, as happened with Roger Federer this year after a year off to nurse injuries and change up his game. Djokovic was #1, has slid to #7; meanwhile Federer's back at #2, just under Rafael Nadal.

Question is -- will fancy Beverly Hills salads and alkaline water help get Djokovic back in the game? We're pretty sure Agassi's got Novak doing some other stuff too ...