The 26-year-old professional golfer wore the pants as part of his relationship with Ralph Lauren's RLX brand.
"I'm sort of game for anything," he said. "It's gonna be fun wearing them on a Sunday."
Horschel's flamboyant look may have had golf watchers buzzing. But Marty Hackel, of Golf Digest, is a fan.
"I love them not only because they're fun but because we're finally getting people to pay attention to what guys are wearing. They're putting smiles on people's faces." he said.