Former heavyweight champion Mike Tyson pleaded not guilty Monday to charges of drug possession and driving under the influence of drugs.

Tyson spoke only to give his name and his birth date during the brief hearing before Maricopa County Superior Court Commissioner Lisa Vandenberg, who entered the plea on Tyson's behalf. Tyson stood with his arms crossed while Vandenberg spoke to his attorneys.

Tyson was indicted earlier this month on felony drug possession and paraphernalia possession counts and two misdemeanor counts of driving under the influence of drugs. If convicted of all four charges, he could be sentenced to up to 7 1/2 years in prison.

Maricopa County Attorney Andrew Thomas has said he would pursue prison time for Tyson, who was convicted of rape in Indiana in 1992 and pleaded no contest to misdemeanor assault charges in Maryland in 1999.

The latest charges stem from Tyson's Dec. 29 arrest in Scottsdale. Tyson was pulled over after leaving a nightclub, and an officer found bags of cocaine in his back pocket and another in a package of cigarettes in his car, according to court records.

Tyson is due back in court Feb. 26.

Tyson, who recently got back in the ring for a series of four-round exhibitions, became the youngest heavyweight champion in history at 20 in 1986, when he knocked out Trevor Berbick. Four years later, he was knocked out by James "Buster" Douglas. By 1997, Tyson's career hit a low point when he bit Evander Holyfield's ear during a fight.