McGill departed Rovers in August 2007 and he rejoined his former club Mount Merrion YMCA later that month. McGill's second stint at Mount Merrion was again short-lived when he made a return to League of Ireland First Division action by signing for Shelbourne on 29 November 2007. McGill made his Shelbourne debut in a scoreless draw against Dundalk at Tolka Park on 7 March 2008. He scored his first Shelbourne goal during a 1-0 victory over Wexford Youths at Tolka Park on 17 October 2008. During the 2011 season he was injured against Salthill Devon ruling him out for the rest of the season.