Philadelphia Phillies outfielder Odubel Herrera was arrested Monday night after cops say he roughed up his 20-year-old girlfriend during an altercation in an Atlantic City casino.
According to the Atlantic City Police Department, Herrera and his GF got into a dispute at the Golden Nugget Hotel and Casino during the Phillies' off day Monday.
Cops were called to the scene ... and when they saw the woman, they say she had visible injuries on her arm and neck.
Cops say they found 27-year-old Herrera in his hotel room after the incident ... and arrested him on the charge of simple assault.