Why are Nike's World Cup kits bulging at the shoulder?

World Cup kits are a big part of the experience for many football fans around the globe, with new releases more important for some than the group stage draw.

World Cup 2026 boasts a bumper range. 48 squads will compete at the finals tournament in the United States, Canada and Mexico this summer and each one will have two or three World Cup kits in their luggage.

When the kits are revealed for participating federations many months before each World Cup, the manufacturers showcase their technological advancements. In this instance, the design innovations profess primarily to combat the effects of playing in very hot weather.

Some of Nike's World Cup 2026 kits have an unfortunate design flaw

That's certainly the case for Nike, whose kits for the finals have been produced with performance in extreme temperatures in mind, but the American sportswear giant was hit with an unwelcome distraction during March's international fixtures.

A number of the brand's international shirts were seen to bulge at the shoulders as if the fabric bunched up at the seam, creating a look that might be classed as rather elegant in a British period drama but is a little unexpected on the broad frame of France captain Kylian Mbappe.

Nike will kit out some of the top contenders at World Cup 2026, several of whom have experienced the shoulder fault. Brazil, Croatia, England, France, the Netherlands, Uruguay and co-hosts United States and Canada are all among Nike's partner federations.

After the shoulder bulge came to light on the international stage and reportedly in retail versions too, Nike acknowledged the problem and explained what will happen next in a statement as the days tick away towards the opening game on Thursday, June 11.

"During the recent international break, we observed a minor issue with our Nike national team kits, most noticeable around the shoulder seam," a spokesperson told The Guardian.

"Performance is unaffected, but the overall aesthetic is not where it needs to be. We always hold ourselves and our products to the highest standards and this fell short.

"We’re working quickly to make this right for players and fans, because every kit should reflect the care, precision and pride that the game deserves."

Correcting the flaw on the scale of retail production is likely impossible and it's unclear how much can be done at the technical supplier level for player issue equipment in such a short period of time.

Performance kit design, development and production is a large and lengthy undertaking that operates years in advance. Patching this problem in time for the summer is a mighty challenge.

Nike's first appearance at World Cup 2026 will be in the second match of the first day. South Korea take on Czechia at Estadio Akron in Zapopan in Mexico.