Jahvid Best's concussion injury could keep him out of the Lions' matchup with the Falcons on Sunday.

Jahvid Best's concussion injury kept him off the practice field Wednesday, and his status is in doubt for the Detroit Lions' game against the Atlanta Falcons on Sunday.

On pace for a breakout year in his second NFL season, the Lions running back Best suffered the third concussion -- and the second of his brief NFL career -- when he had to leave the Lions' first loss of the season last weekend against the San Francisco 49ers.

When talking to reporters after practice Wednesday, Best wouldn't offer much as to whether he would be able to suit up this weekend. He is officially listed as questionable on the Lions' injury report.

I have no idea, Best told reporters Wednesday when asked whether he would play against the Falcons.

This is Best's third concussion, and second this season. He also suffered a concussion during the Lions' second preseason game this season. And a 2009 fall -- not on the football field -- also gave him a concussion.

Best left the Lions 25-19 loss to the 49ers -- the one during which those two coaches, you know, those two grown men, Jim Schwartz and Jim Harbuagh, nearly got in a fight -- early in the fourth quarter.

He had a hard time with some of the lights after the game, Schwartz told reporters. Those are signs that you've got to be concerned about and you have to be objective about. We'll have a whole protocol that he has to go through to get back on the field.

Coming back from a concussion isn't like coming back from a sprained ankle or a bad shoulder or a pulled hamstring. Some of those things you can tough out. You can't tough out a concussion.

Best's injury gives the Lions few options out of the backfield, where the duties will be left to newly acquired Ronnie Brown or untested young players Maurice Morris and Keiland Williams.

The Lions traded for Brown from the Philadelphia Eagles on Tuesday, perhaps feeling the need to address the running back situation with Best's injury.

Brown did not practice Wednesday either, but he will likely have to take some carries Sunday. His adjustment to the offense shouldn't take too long, as he has played under Lions offensive coordinator Scott Linehan.

But Brown is far from the Best (sorry) option. Best has rushed for 390 yards this season (at a 4.6 yards-per-carry clip), caught 27 passes for 287 yards and not fumbled once.