For more than a year, Carolina Panthers defensive end Frank Alexander said all the right things. His actions haven't backed up those words.

The NFL announced Tuesday that Alexander was suspended for at least one year after violating its substance-abuse policy for a third time.

The Panthers supported Alexander through four- and 10-game suspensions last year, but it will be hard to justify keeping him around after a third strike.

A fourth-round pick in 2012, Alexander has 3.5 career sacks, and he's played in just one game the past two seasons. He was scheduled to be a restricted free agent in 2016.

Alexander previously said he's used marijuana to deal with family issues and pain. In training camp, he again pledged he had kicked his habit, but his year ended when he tore his Achilles in the preseason.

After gliding through the season without any off-the-field problems of note, the Panthers have had three players suspended in less than 24 hours. On Monday, defensive end Wes Horton was sat down for four games and injured wideout Stephen Hill was given one.