We are here today with an exercise on "How to leave your receiver out to dry" with professor Brady Quinn.

KC Chiefs QB Matt Cassel lasted two series' on Friday night before stepping aside for the first backup quarterback, Brady Quinn. He came in near the end of the first quarter and, frankly, looked average at best as he completed 7-of-13 passes with one pick.

He also let a pass sail a little too high which nearly resulted in Chiefs receiver Terrance Copper getting decapitated at the hands of Adrian Wilson.

Copper is fine, luckily. Back at practice and all that. This is the type of play that can hurt some very badly.

Copper's crossing the middle of the field, from right to left. Adrian Wilson is the safety. You can already tell this won't end well. Quinn sails the ball a little too high, just high enough that Copper jumps for it but can't get a hand on it.

So Copper doesn't catch the ball. Wilson has an unimpeded path to Copper. Copper is completely exposed at this point.

He tries to bring his arm down a little bit to protect himself but he pretty much gets laid out. Wilson leads with his shoulder and crashes into Copper's chest. This is basically the last legal way to apply a bone crushing hit. But Copper is defenseless; was this an unavoidable hit for Wilson? That's something the league office will have to determine. The TV broadcast announcers seemed to think this was legal, focusing on whether Wilson made the hit in Copper's neck/head area.

You can tell by this screen shot how big this collision must've been. Copper's momentum is heading up the field and then -- BOOM! -- his momentum is reversed. Pretty sure that's not a change of direction your body should be seeing as a result of blunt force.

That's called de-cleating.

This is the end result. Copper started to get up a little bit remained down until the Chiefs medical staff -- Univ. of Kansas Hospital KC Chiefs Medical Staff? -- helped him off the field.

Copper, by the way, appears to be fine following the hit. Still, a potentially scary moment.