Alexander Isak is now eligible to play for Borussia Dortmund after FIFA approved his transfer from AIK Solna, although he has been left out of the club's Champions League squad.
Isak, 17, joined Dortmund from AIK last month but FIFA's Player Status Committee had to validate the deal as clubs signing minors need to fulfil certain standards under the governing body's "Regulations on the Status and Transfer of Players."
Clubs need to comply with obligations which "ensure that the player is looked after in the best possible way" and guarantees "an academic and/or school and/or vocational education and/or training, in addition to his football education and/or training, which will allow the player to pursue a career other than football should he cease playing professional football."
After FIFA approved the transfer on Thursday, Isak was granted permission to play in the Bundesliga and the DFL Pokal by the German Football League and the German Football Association.
Dortmund said in a statement that the approval of the transfer "was granted more quickly than BVB expected," but added that to gently ease the player into Bundesliga life "the decision has been taken together with Isak and his parents not to nominate the player for the current UEFA Champions League campaign."
Dortmund loaned Adrian Ramos to La Liga club Granada last month and so have registered 20-year-old Mikel Merino for the Champions League knockout stages in his place.