Cincinnati Bengals' LB Vontaze Burfict is facing a four-game suspension for violating the NFL's performance-enhancing drug policy, pending appeal, per league sources.

Burfict's appeal will center around the fact that he was on prescribed medication for the concussion he suffered on a hit from Steelers' wide receiver Ju-Ju Smith Schuster on Dec. 4 and that he suffered a Grade 3 shoulder AC sprain during the Detroit Lions game on Dec. 24 and was on prescribed medications for this injury as well, per another source.

The disputed test occurred Dec. 27, when Burfict already had been ruled out for the season, and he is expected to argue that he could not be using any drug to gain an advantage when he wasn't even playing.

No appeal date has been set yet, but Burfict soon will be fighting to be able to play the first four games of next season.

Burfict has been suspended in the past, but for on-field transgressions. He was suspended for the first three games of the 2017 season for an illegal hit on Kansas City Chiefs fullback Anthony Sherman in the preseason. He initially was suspended five games but had the penalty reduced on appeal.

Burfict was also suspended the first three games of the 2016 season for numerous violations of player safety rules, including an illegal hit on Pittsburgh Steelers wide receiver Antonio Brown during the 2015 playoffs.

Separate from those suspensions, Burfict has been fined $303,637 for 11 on-field incidents in his NFL career, according to ESPN Stats & Information.