DeSean Jackson exits after hard hit

PHILADELPHIA -- Philadelphia wide receiver DeSean Jackson suffered a concussion and Atlanta cornerback Dunta Robinson injured his head in a nasty head-on collision in the second quarter of Sunday's game.

Eagles coach Andy Reid gave no estimate how long Jackson might be sidelined. Same thing for Falcons coach Mike Smith about Robinson.

"He seems to be fine," Smith said of the cornerback Atlanta signed as a free agent in the offseason. "It was a very violent collision. I saw him and knew he couldn't return, and that's all I really know."

Both players stayed on the turf for several minutes before being helped from the field. Jackson dropped a pass when hit by Robinson, who led with his head and hit Jackson in the helmet. Robinson was flagged for hitting a defenseless receiver.

Jackson had scored both of Philadelphia's touchdowns and the Eagles led the Falcons 14-0 at the time of the collision. Philadelphia won 31-17.

"That was scary," Eagles receiver Jeremy Maclin said.

Eagles quarterback Kevin Kolb, who was sidelined by a concussion after starting the season opener, was asked what he would tell Jackson.

"Take it seriously because it is serious," said Kolb, who returned to practice before the Eagles' third game but didn't get back on the field until Michael Vick was injured two weeks ago in a loss to Washington. "I just felt so bad. I'm part of the play, and I never saw the guy.

"DeSean is a tough guy and he'll be out there as soon as he can, we got to take this concussion situation serious."