The disputed test occurred Dec. 27, with Burfict already ruled out for the remainder of the season, according to Schefter. His appeal reportedly will be based on the fact he was on prescribed medication for a concussion suffered in a Dec. 4 game against the Pittsburgh Steelers and a Grade 3 shoulder AC sprain sustained in the Bengals' Week 16 bout with the Detroit Lions.
No date has yet been set for the appeal.
If Burfict loses the appeal, $11.3 million in guaranteed money from his three-year, $33-million contract would become void, according to NFL Network's Ian Rapoport.
Burfict, 27, played and started 10 games last season. He was to be suspended five games to start the year due to a hit on Kansas City Chiefs fullback Anthony Sherman in the preseason, but it was later reduced to three games.
The six-year veteran finished the season with 69 combined tackles, 1.5 sacks, and one forced fumble.
Burfict also missed the beginning of the 2016 season due to a three-game ban for repeated violations of player safety rules, after a hit to the head he made on Pittsburgh Steelers wide receiver Antonio Brown in the wild-card round of the previous season's playoffs.