The Kansas City Chiefs suffered an upset loss at the hands of the Oakland Raiders on Thursday night, but that is far from their biggest problem. Star safety Eric Berry complained of chest discomfort following the game and on the following day, and doctors now believe that he may have lymphoma, a type of cancer.

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According to media reports, at a Monday press conference, Chiefs trainer Rick Burkholder told reporters, "At this point in time, we don't have a definitive diagnosis. But the leading consideration for what he has right now is lymphoma."

Burkholder went on to say that he was first alerted that there may be a problem when Berry continued to complain of chest discomfort on Friday. "It just didn't quite add up to an orthopedic injury," said Burkholder.

The Chiefs put Berry through a series of tests, beginning with a chest X-ray. After that came back negative, they continued tested, and eventually an MRI revealed the mass in his chest. According to Burkholder, all Kansas City players received a battery of tests during the offseason as part of their treatment program, and Berry had shown no symptoms prior to Thursday night.

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The Chiefs have placed Berry on the season-ending non-football illness list. He is scheduled to head to Emory University Hospital in Atlanta for further testing and a definitive diagnosis. Berry addressed his teammates before leaving them, and he released a statement through the organization thanking everyone for their support and indicating that he fully intends to play in the NFL again.