L.A. Clippers -- TEAM STEAK DINNER ... To Prep for the Playoffs

The team that eats together, WINS together -- at least, that's what the Clippers are hoping for because the entire squad got together for a pre-playoffs dinner last night ... and TMZ Sports has the footage.

Blake Griffin, Matt Barnes, Big Baby Davis and the rest of the squad met up at Mastro's Steakhouse in Beverly Hills ... where Barnes explained that it wasn't a celebration, but rather a preparation.