Dennis Rodman Was On Probation During DUI Arrest, Jail Likely

Dennis Rodman's DUI problems have gone from bad to worse ... because he was on probation during his arrest on Saturday -- and it likely means he'll be thrown in the slammer.

The probation stems from a plea deal Rodman struck over a July 2016 wrong way crash -- where he was going the wrong way on an Orange County, CA freeway, struck a car and allegedly fled the scene. Witnesses also saw him drinking at a karaoke bar before the crash but he was not charged with DUI for that incident.

However, Rodman was placed on 3 years probation with the condition he stay out of trouble. It was a good deal for Rodman, considering he was facing up to 2 years in prison.

So, what happens next? Officials will likely revoke his probation in the wake of the new arrest and he could be sent to prison for the full 2 years he was originally due to serve in the wrong way crash case PLUS any additional time for the new arrest.

Rodman's rep has told TMZ Sports the NBA player needs rehab -- but it could be too little, too late.