Jordan Clarkson is having a hell of an off-season -- as demonstrated in this video of the L.A. Lakers player in a heated game of beach volleyball ... with a bunch of hot chicks in thong bikinis.

Clarkson and his Oklahoma City Thunder pal, Andre Roberson, hit up the nets at Hermosa Beach, CA this past weekend -- went shirts off -- and got into a bit of a 2-on-3 situation in the sand.

The chicks sucked at volleyball ... but who cares?!

Clarkson has a knack for attracting beautiful ladies ... he's recently been connected to Kendall Jenner.