CHARLOTTE, N.C. -- The Carolina Panthers activated defensive end Frank Alexander to the 53-man roster on Monday and placed wide receiver De'Andre Presley on injured reserve.

Presley suffered a concussion in Sunday's 17-13 victory over Cleveland.

Alexander was suspended for the first 14 games for violating the NFL's substance abuse policy on two separate occasions. The second suspension, 10 games, ended last Monday and the Panthers (6-8-1) had seven days to activate him.

Alexander has played in 28 games with six starts. He has 3.5 sacks, five passes defensed and three fumble recoveries. Coach Ron Rivera's most valuable player in training camp, the fourth-round pick out of Oklahoma in 2012 is considered one of Carolina's most versatile ends.