Both Letroy Guion (three games) and Datone Jones (one) were suspended to open the 2015 season because of marijuana arrests.
Mike Neal, who is a free agent, was suspended four games to open the 2012 season.
Neal’s suspension was for performance-enhancing drugs. Pennel’s is for substance abuse, which we’re going to guess means he tested positive for marijuana.
The NFL doesn’t release the reason for the suspension.
The four-game suspension also means this isn’t the first time this has happened.
Players receive no suspension for their first violation. They only receive a suspension after failure to comply, so either a second positive test, missing a test entirely or not participating in the required treatment program.