Watch: Riley Cooper forgot to pay attention while teammate fumbles

Don't stop until your hear the whistle.

Philadelphia Eagles wide receiver Riley Cooper failed to do that on Sunday night against the Dallas Cowboys. With the Eagles driving in the second half, QB Mark Sanchez found tight end Brent Celek over the middle for what looked to be a nice gain. Cooper was standing right there and turned away from the play to celebrate a first down.

But ...

Celek fumbled and although Cooper may not have been able to recover the ball, he could have dove in there and possibly jarred it loose for a teammate to scoop up. What's more, it just looks bad.