The Calgary Stampeders have launched an investigation into Brendan Langley ... after their wide receiver was seen on video punching a United Airlines employee at a New Jersey airport this week.
The Canadian Football League club released a statement late Monday announcing the probe ... saying it is aware of Langley's arrest and is "looking into the matter in order to learn the full details."
"[We] will have no further comment until the investigation is complete," the team said.
Langley -- who just signed with the Stampeders in February -- got into a brawl with the UA employee at the Newark Liberty International Airport after an argument.