Novak Djokovic entered the French Open this week as the top tennis player in the world. But you wouldn’t know it by the clothes he wears. Unlike rivals Roger Federer and Rafael Nadal, both endorsed by Nike, Djokovic has until recently worn outfits by Sergio Tacchini, a small Italian label. The designs—one memorable get-up featured a tattoo-like dragon outline—have not been a hit with North Americans who prefer staid polos. Last week, the Serbian star cut ties with the label for a new deal with fashion retailer Uniqlo, which is not known for tennis gear at all but is aggressively opening stores in the United States. The Japanese-based firm is no Nike, but it has the deep pockets to offer Djokovic the marketing payday that has eluded him. And while the terms of the deal weren’t disclosed, if Djokovic wins a historic fourth Grand Slam in a row at Roland Garros, the exposure for Uniqlo could be priceless.