The concept has been created by Stockholm-based digital agency Perfect Fools and centres on a multi-lingual content-rich website with offshoots in social media, blogs and point of sale.
Under Armour was founded in the US in 1996 by a former American football player to sell performance sports clothing which keep athletes cool and dry.
It has launched into the football boots market, taking on giants such as Nike, with two models.
The website showcases 11 semi-professional and amateur players picked from across Europe to form the Under Armour 11 "test team", such as Hanwell Town FC striker Blaise O'Brien.
When users click on an individual player he introduces himself and his preferred boots, UA Dominate or UA Create.
They can then see what Under Armour products he uses (from boots to clothes and bags) and a one-minute video documentary about him.
The website also has a "join the squad" feature which gives users the chance to be picked for future Under Armour 11 test teams.
Mark Chalmers, creative partner at Perfect Fools, said: "Under Armour has a reputation for market-leading sportswear and is launching into the football sector with boots already tested and scored with by professionals.
"We are targeting tough, dedicated players who never say die."