NFL's Calais Campbell Says His Friends on Raiders Believe In Connor Cook (VIDEO)

Here's some inside the locker room info from Arizona Cardinals stud defensive end Calais Campbell ... who says his friends on the Raiders TRULY believe they can win with Connor Cook.

Then again, Campbell says they really don't have another choice ...

The 2 time Pro Bowler says he's also convinced Oakland can get it done against the Houston Texans this weekend with the 3rd string QB at the helm ... and his reasoning is pretty good.