PGA veteran Jason Day donned a full grey sweatsuit on Sunday at Pebble Beach, drawing gasps and harsh critiques from across the fashion-conscious golf world.

The 37-year-old Day shot a final-round 69 at the famed Northern California course, coming in tied for 13th at a 12-under 269.

But it wasn’t his play that raised eyebrows on Sunday — it was what he was playing in.

Day could’ve easily been mistaken for any random guy putting around a par 3 public course on Sunday, donning grey sweatpants and a grey crew sweatshirt that had no distinguishable markings aside from a cursive M on his upper left chest.

The M stood for his clothing sponsor, Malbon Golf, which seeks to “honor the heritage of golf while opening it up to a broader community, blending time-honored values with a fresh, creative spirit,” according to the Los Angeles-based brand.

One golf fan asked the PGA: “Will you please explain to us how Jason Day was allowed to play Pebble Beach in a sweatsuit?”

Another viewer said Day’s untraditional take on golf attire is fine, but “wearing a sweatsuit on the final day at Pebble is ridiculous.”

While professional golfers don’t have a uniform, akin to team sports, their attire is relatively standard — khakis and a simple short-sleeved polo shirt.