The agreed upon Detroit Lions-Philadelphia Eagles trade of Jerome Harrison for Ronnie Brown was voided because Harrison has a brain tumor, according to a report.

The two teams agreed to the deal of the running backs right before the NFL's Tuesday trade deadline, but the deal was voided because Harrison failed his physical with the Eagles.

ESPN's Adam Schefter reports that Harrison failed because of a brain tumor unknown to either the Lions or Eagles.

Schefter tweeted on Thursday morning, Without trade, Jerome Harrison doesn't get physical. Without physical, doctors don't find brain tumor. Trade might have saved his life.

Neither Harrison nor the Lions have publicly commented on his illness, but a brain tumor would likely sideline him for the rest of the season.  

Harrison joined the Lions as a free-agent this off-season after spending a year with the Philadelphia Eagles. The former Washington State running back had his best season with the Cleveland Browns in 2009 when he rushed for 286 yards and three touchdowns in one game -- good for third all-time for a single game.