Images of the graffiti, with the message ‘thanks for the memories’ alongside the outgoing Parkhead captain’s name, have been circulated by Celtic fans group The Green Brigade on social media.
Brown agreed a pre-contract deal with Aberdeen on Thursday after being pictured at the club’s training ground, and called time on a 14-year career at Celtic who he joined for £4m from Hibs in 2007.
The midfielder will take up a player-coach role at Pittodrie and will link up with former Easter Road team-mate Stephen Glass. The former Dons midfielder was confirmed as manager earlier this week after coaching in America’s MLS.
Celtic cast their own online tributes to the departing captain, who played more than 400 times for the Parkhead club, won 22 trophies over 14 seasons and earned 55 Scotland caps.