An NFL official had to be taken off the field on Sunday on a stretcher ... after he suffered a gruesome leg injury following a sideline collision with Alvin Kamara.
The play happened in the second quarter of the Saints' matchup with the Lions in New Orleans ... when Kamara took a pitch from Derek Carr and accelerated toward the first-down marker.
On his way, though, a Detroit defender shoved him out of bounds ... and when he went crashing toward the turf, his momentum carried him right into the knee of a game official.