There was so much about Cavan Sullivan’s performance to capture attention that, for many watching, his brightly coloured footwear may barely have registered.After all, as the recently concluded World Cup has taught us, pink boots have become nearly ubiquitous.But while the 16-year-old Sullivan produced a star display as he played 85 minutes during his team Philadelphia Union’s 3-1 win over New York Red Bulls in Major League Soccer on Thursday, he was breaking new ground even as he glided across it.Sullivan, who agreed a deal to join Manchester City in the Premier League when he was just 14 and became the youngest player to ever appear in an MLS match two years ago, was marking another first at Subaru Park. The teenager was giving a specially constructed pair of 3D-printed Adidas cleats their own debut in top-level competitive football.The lightweight boots were printed to match the exact specifications of Sullivan’s feet, as part of the sportswear brand’s Project R.A.P. (Radical Athlete Perception) range.Sullivan wearing the boots against New York Red Bulls (Mitchell Leff/Getty Images)Adidas launched Project R.A.P. in March as a new way of making sports products which are bespoke to different sports and athletes.The boots were also directly shaped by athlete feedback, testing and data. Paris Saint-Germain star Khvicha Kvaratskhelia and Atletico Madrid forward Ademola Lookman were consulted in the development process, and the pair are also set to wear the boots in the forthcoming season.