How's the best NFL draft prospect in the country celebrating his final weeks as an unmarried man??
VEGAS, BABY!!!
TMZ Sports has learned Trevor Lawrence hit up Sin City for a low-key bachelor party over the weekend -- bro-ing down at a casino table with his pals and living it up just days before he's set to marry his longtime GF, Marissa Mowry.
A witness tells us the 21-year-old ex-Clemson QB was at Mandalay Bay at around 11:30 p.m. Sunday ... gambling with some buds and keeping his surgically repaired left shoulder safe in a sling.