The Football Association is looking into comments made by Robert Huth on social media, according to reports.
The Stoke City defender is believed to have made comments on Twitter in reply to an account which posts sexual images of people, and asks users to guess their gender.
The German has deleted the tweets and issued an apology, writing: "Clearly no offence was meant or directed to anyone, but apologies if I've offended anyone."
Sky Sports News has said that the FA is looking into the incident, which is the latest in a series of social media investigations this season with both Rio Ferdinand and Mario Balotelli having received bans previously.
Huth has struggled with injuries this season and has made just three appearances for the Potters.