Drew Lock is VERY fortunate to be uninjured today ... cops say a stray lug nut smashed into the QB's windshield on the road on Wednesday -- but, thankfully, it didn't hurt the NFL star.
The Kansas Highway Patrol assisted Lock after his car had the run in with the wheel nut ... and in pictures they posted, you can see just how close Lock was to catastrophe.
The nut hit the Denver Broncos signal-caller's ride so hard .