Pulisic is a 16-year-old attacking midfielder, who has starred for the Americans' U-17 team and agreed to join BVB last year. But FIFA rules bar minors from going abroad to play for teams, which is why Pulisic needed to get a passport from a European Union country to be able to play. He applied for a Croatian passport, which he was eligible for through his grandfather, and has received it.
In recent months, Pulisic has been going to Dortmund for short training stints, where he played with the U-17 and U-19 teams, but he couldn't join them full-time until now.
Pulisic is an extremely skillful player who has been praised for his creativity. He doesn't rack up goals, but that hasn't stopped him from being the focal point of all of his teams, flashing the promise that didn't just make him one of the most promising Americans, but drew the attention of BVB.
Considering Dortmund's history, which saw them buy and develop both Shinji Kagawa and Mario Gotze, there are few clubs it would be better to see Pulisic go to. Jurgen Klopp looks to be the perfect coach for the young American, and now he'll be there full-time as he tries to make good on his immense potential.