Former Dallas Cowboys 1st-round pick Marcus Spears is going after a current player over a tackle he thought was dirty as hell ... calling the play straight-up "bullsh*t."
Here's the deal ... in the 4th quarter of the Cowboys' game against Seattle on Sunday -- defensive lineman Trysten Hill made an ankle-grabbing stop on 'Hawks star Chris Carson.
After the play, the RB was down on the ground in pain holding his knee ... and when the replay aired -- it wasn't hard to see Hill twisting the guy's leg well after he was down.