Former NBA star Jalen Rose was just sentenced to serve 20 days in jail -- four months after he crashed his car into a ditch during an alleged drunk driving incident in Michigan back in March. TMZ broke the story ... the 38-year-old ex-Fab Fiver was driving along an icy roadway with a female passenger on March 11 when he lost control of his vehicle and crashed, flipping the car. When cops arrived, Rose agreed to undergo several roadside sobriety tests -- and was eventually arrested for DUI. Along with the jail time, Rose was also sentenced to 1 year of probation.20 days in jail? This will damn sure make people think twice about drinking and driving (or will it?!?!).