John Guidetti's season-long loan move from Manchester City to Celtic has been completed after Fifa allowed the move to go ahead.
Paperwork to register the Swedish striker was filed after Monday's transfer deadline.
The Scottish FA and Scottish Professional Football League asked Fifa for dispensation for the 22-year-old's proposed move to Glasgow.
However, Guidetti is not registered for Celtic's Europa League campaign.
Uefa's deadline for squad filing expired at midnight on Tuesday. Should Celtic progress from Group D, they could register Guidetti for the knock-out rounds.
A Fifa spokesperson said: "After checking the documentation received and the information contained in the international transfer matching system managed by Fifa TMS, the Scottish Football Association was informed today that the envisaged loan deal may proceed."
Guidetti enjoyed a prolific spell on loan at Feyenoord in the Netherlands in season 2011-12, but failed to find the net during a stint with Stoke City last season. He is in the final year of his deal at the Etihad Stadium.
He could further bolster the Scottish champions' attack following the capture of Serbian striker Stefan Scepovic.
Cardiff City's Jo Inge Berget, City's Jason Denayer, Rubin Kazan's Wakaso Mubarak and Aston Villa's Aleksander Tonev have all moved to Celtic on loan while goalkeeper Craig Gordon joined as a free agent.
And, speaking to Celtic's website, Guidetti said: "Everybody knows what a great football club this is, especially in Sweden when Henrik Larsson was playing here. It's also a very well-known club because of the fans, who are so passionate and brilliant.
"I'm just going to work my socks off to try to do my absolute very best every game and give 100% because that's what the fans deserve."