NEW YORK, NY – MARCH 11: Kevin Plank, chairman of Under Armour Inc., speaks at a news conference March 11, 2013 New York City. Plank was on hand with General Electric CEO Jeff Immelt and NFL Commissioner Roger Goodell to introduce an initiative and research program to study concussions in an effort to improve the safety of professional football players, (Photo by Allison Joyce/Getty Images)

Under Armour CEO Kevin Plank leaves Trump’s American Manufacturing Council

LOUISVILLE, KY – NOVEMBER 04: Kevin Plank (R), owner of Breeders’ Cup Filly & Mare Turf entrant Shared Account, talks in the paddock during the 2011 Breeders’ Cup World Championships at Churchill Downs on November 4, 2011 in Louisville, Kentucky. (Photo by Rob Carr/Getty Images)

Under Armour’s CEO Kevin Plank has been sending weird Christmas cards to Nike’s Phil Knight every year