St. Louis Rams running back Isaiah Pead will be suspended without pay for the first game of the 2013 season for violating the NFL Policy and Program for Substances of Abuse, according to

The suspension means Pead will miss the Rams’ season opener against the Arizona Cardinals on Sept. 8. He will be eligible to return to the active roster a day later. Pead is eligible to participate in all offseason and preseason practices and games.

Pead, the 50th overall pick in the 2012 NFL Draft, carried the ball 10 times for 54 yards in 15 games last season.