Per ESPN's Adam Schefter, Irving is "under evaluation" by the NFL for a potential suspension.
Irving has been missed the first four games in each of the past two seasons due to drug suspensions. His 2017 suspension was the result of a failed test for performance-enhancing drugs.
Last season, the NFL announced Irving was being suspended for violating the league's substance-abuse policy.
Schefter didn't specify what Irving was under evaluation for. The report comes after the Cowboys were already preparing for the loss of one defensive lineman for the time being.
Per NFL Network's Ian Rapoport, Randy Gregory reportedly was suspended indefinitely for violating the NFL substance abuse policy and terms of his conditional reinstatement.
Irving only played in two games last season due to suspension and injuries. The 25-year-old set a career high with seven sacks in just eight games during the 2017 campaign. He will be a free agent when the new league year begins on March 13.