Former Dallas Cowboys star Mike Jenkins was involved in a heated confrontation at a Florida bar over the weekend ... video obtained by TMZ Sports shows.
The incident happened at The Kenwood on Sunday night in St. Petersburg ... after Jenkins had apparently become upset with the way one of the establishment's employees had handled his credit card.
A witness tells us the worker had either misplaced or lost Jenkins' plastic -- which agitated the former 2008 NFL Draft first-round pick.
According to the witness, after making a scene inside the bar, Jenkins -- a University of South Florida alum -- then went outside and screamed at a security guard at the door.