Horton’s suspension is effective immediately, meaning he will not be available until Dec. 21, the day after the Panthers’ Week 15 game against the New York Giants.
Horton, 25, has started two games this season, tallying eight tackles and a sack. He started all but one regular season game in 2014, finishing the year with 29 tackles, three sacks and two forced fumbles.
Horton spent a week as a free agent this season after he was cut by Carolina following Week 3, but the team re-signed him ahead of Week 5.
Wide receiver Stephen Hill, who is on injured reserve with a torn ACL, also received a one-game suspension for violating the league’s substance abuse policy. The suspension will essentially be a deduction of one week’s pay.
The Panthers (10–0) will play the Dallas Cowboys (3–7) on Thursday.