Running back Rashaan Salaam, attempting a comeback with the Oakland Raiders, says an addiction to marijuana made him withdrawn, caused him to fumble and nearly ended his career.

Salaam, who won the Heisman Trophy at Colorado in 1994, was plagued by fumbles with the Chicago Bears, losing 14 in 31 games. He thinks the fumbles most likely were related to marijuana. "It probably had me out there lackadaisical instead of being out there 100 percent," he told ESPN in an interview Sunday.

"Everybody thinks getting high is cool, you can let it go when you want to let it go," he added. "But it's just as potent as alcohol. It's just as potent as cocaine."

PACKERS: Wide receiver Robert Brooks retired yesterday after seven injury-plagued seasons with Green Bay. He said his knees, back and hamstrings could no longer withstand the punishment of pro football. "You can fool a lot of people, but you can't fool yourself," he said. "I'm 29 years old, and after a practice, I feel like I'm 50."

BEARS: Chicago signed first-round draft pick Cade McNown to a seven-year deal that includes a $6.1 million signing bonus. The quarterback's agent said the deal could be worth $22 million with incentives and the signing bonus.

VIKINGS: Rookie defensive end Dimitrius Underwood, the 29th overall draft pick, skipped yesterday afternoon's practice and team officials do not know why.

A team official said Underwood, drafted out of Michigan State, was neither ill nor injured.

The 6-foot-6, 276-pound rookie signed a five-year contract on Sunday for more than $5 million with a signing bonus of $1,750,000.

CARDINALS: Wide receiver David Boston, Arizona's top pick in the draft, reached a contract agreement with the team. The deal is four years for $7 million with a $3.8 million signing bonus. Boston had missed the first four days of training camp.

JETS: New York re-signed 14-year veteran fullback Keith Byars to a one-year contract.