The violation was first reported by Deportivo Z 101 in the Dominican Republic.
Cano suffered a fractured fifth metacarpal in his right hand when he was struck by a pitch from Detroit’s Blaine Hardy on Sunday. He was scheduled to see a specialist Tuesday.
The 35-year-old Cano is one of the Mariners’ biggest stars, having hit 23 home runs last season after getting 39 in 2016.
He was batting .287 with four home runs and 23 RBIs this season, his fifth with Seattle. Cano hadn’t missed a game this season and hasn’t played in fewer than 150 games in any of the past 11 seasons.