More roster shuffling for Lions' backfield

The Detroit Lions have officially ended the season of running back Jerome Harrison, placing him on the reserve/non-football injury list. Harrison was diagnosed with a brain tumor during a physical following his since-voided trade to the Philadelphia Eagles, according to ESPN's Adam Schefter.

Taking Harrison's spot on the roster is third-year player Eldra Buckley, who spent the past two seasons with the Eagles and worked out with the Lions this week. He had 31 carries in 2009 and 2010 combined, but played in all 32 regular-season games over that stretch.

With Harrison now sidelined, and the immediate future of starter Jahvid Best in doubt because of a second concussion in three months, the Lions presumably will move forward with veteran Maurice Morris as their top running back. Keiland Williams, a waiver claim last month who has 19 carries this season, will also be part of the rotation.

Earlier: Should Best sit out the rest of the season?