Former NBA 1st round draft pick Isaiah "J.R." Rider was arrested in Arizona this week for violating his probation ... TMZ has learned.
Rider -- who played in the NBA from 1993 to 2001 -- is currently behind bars in Maricopa County on a no-bail hold. It's unclear why police believe Rider violated his probation.
Rider's probation stems from a 2010 incident -- where he fled from police after they tried to pull him over for driving erratically. He pled guilty to unlawful flight from a law enforcement vehicle.
Rider has had a long history of run-ins with police -- over the years, he's been arrested for fraud, battery, domestic violence, false reporting, kidnapping and possession of narcotic drugs.
Rider was an NBA journeyman -- who played for the Los Angeles Lakers, Minnesota Timberwolves, Atlanta Hawks, Portland Trail Blazers and the Denver Nuggets.