Phoenix:Mike Tyson has checked himself into an inpatient treatment program for "various addictions" while awaiting trial on drug charges, his lawyer said on Wednesday. "He needed to get involved in something that would help him with his addiction," attorney David Chesnoff said. Chesnoff wouldn't describe Tyson's addictions, but police said the former heavyweight champion told officers that he used cocaine frequently. Chesnoff said Tyson checked himself into an undisclosed facility shortly after appearing in a Phoenix courtroom. The 40-year-old Tyson pleaded not guilty on January 22 in Maricopa County Superior Court to felony drug possession and paraphernalia possession counts and two misdemeanor counts of driving under the influence of drugs. A pretrial hearing is scheduled for February 26. Chesnoff said he'd prefer that Tyson stay in the treatment facility, but "if he's required to be in court and he doesn't get excused, he'll be in court." County Attorney Andrew Thomas has said Tyson has run out of second chances, and prosecutors will pursue prison time. Troubled career If convicted on all four drug charges, Tyson could be imprisoned for as much as 7 1/2 years. A spokesman for Thomas did not return calls Wednesday. Tyson previously was convicted of rape in Indiana in 1992 and pleaded no contest to misdemeanor assault charges in Maryland in 1999. Tyson became the youngest heavyweight champion in history in 1986 when, at age 20, he knocked out Trevor Berbick. Four years later, Tyson was knocked out by James "Buster" Douglas. By 1997, Tyson's reputation sank to a career low when he bit Evander Holyfield's ear during a fight. On December 29, police arrested Tyson in Scottsdale after his BMW was allegedly spotted weaving through traffic, almost hitting a police SUV. When officers stopped him, police said Tyson was trying to wipe a white powder off the console of his car. Tyson had bags of cocaine in his back pocket and another bag in a pack of cigarettes, according to court documents. Police said Tyson told officers he uses cocaine "any time he can get his hands on it."