NHL vet Mark Letestu didn't need a hot dog to enjoy his mustard on Thursday ... 'cause the Winnipeg Jets center downed that yellow stuff straight outta the packet!!
The 34-year-old Canadian turned heads when he was spotted chuggin' some mustard on the bench during the Jets' preseason game against the Edmonton Oilers ... leaving a lot of people wondering what the hell was going on.
Turns out ... it's all in the name of SCIENCE!!! 'cause apparently, mustard has some ingredients like turmeric and vinegar that help prevent cramps.
Hey ... we get it.