The highly-rated defensive midfielder signs for The Reds’ Under 23 side after a loan spell at Dutch side Telstar, penning a contract until 2022.
McGuane, who came through the academy at Arsenal, joined the Catalan giants at the age of 18. He became the first English player to play for Barcelona in 29 years when he featured in the Catalan Super Cup Final in March 2018.
The 21-year-old has also represented the Republic of Ireland and England at youth level, switching to the Three Lions in 2015 and appearing at the 2016 UEFA European Under 17 Championships.