Marcus McGuane has joined Barcelona from Arsenal for an undisclosed fee, the Premier League club have confirmed.
The 18-year-old has completed a medical in Spain and signed a contract that includes a release clause of EUR25million.
The midfielder, who had been at Arsenal since the age of six, made his first two senior appearances under manager Arsene Wenger in Europa League group-stage matches against BATE and Red Star Belgrade this season.
McGuane, an England youth international, will join Barca's B team with a view to earning a spot in the first-team squad in future.
"We would like to thank Marcus for his contribution and wish him well at Barcelona," Arsenal said in a statement.
"The transfer is subject to the completion of regulatory processes."