Liverpool are probing a tweet allegedly made by Nathan Eccleston about 9/11.
The 20-year-old reportedly wrote on Twitter: "I ain't going to say attack don't let the media make u believe that was terrorist that did it," before subsequently deleting the post.
Liverpool, owned by America's Fenway Sports Group, are looking into the matter.
"The club takes this extremely seriously and senior club officials have informed Nathan Eccleston that we are undertaking an investigation into the circumstances surrounding these postings and will decide on an appropriate course of action," a spokesman told the Liverpool Echo.
