City, McGuinness was appointed the team's trainer, only for Kenny to return from Scotland and McGuinness to depart. Celtic The golfer Paul McGinley mentioned McGuinness to Dermot Desmond after speaking with the Donegal manager. Desmond invited McGuinness to several UEFA Champions League games played by the Scottish football team Celtic in Glasgow. On one such occasion, the soccer club's chief executive Peter Lawwell inquired if McGuinness would like to join. On 9 November 2012, Celtic confirmed their intention to appoint McGuinness as a performance consultant on a part-time basis. It was expected that he would remain as the Donegal manager, spending three days each week in Scotland focusing on the soccer club's academy structure at their Lennoxtown training centre. His role at Celtic did not affect his attendance at Donegal training sessions; he attended every one. After a stint as performance consultant, he later took over as youth coach. By 2017, he was assistant manager of the club's under-20 team. Beijing Guoan In June 2017, McGuinness was named as assistant coach of Chinese Super League side Beijing Sinobo Guoan, under coach Roger Schmidt. He resigned for "personal, family reasons" just over six months later in January 2018. Charlotte Independence In December 2018, McGuinness was named as the new head coach of Charlotte Independence in the USL Championship, where he signed a three-year contract. He was unveiled at a press conference in Montrose, South Dublin. He said that if the chance to join Celtic had not emerged, he "would be as still managing Donegal". On 17 January 2019, McGuinness appointed former Athletic Bilbao manager Félix Sarriugarte as his assistant coach. McGuinness also secured the loan signings of defender Andrew Gutman and Scotland national team midfielder Mark Hill, in February and March 2019 respectively. However, on 12 June 2019, McGuinness was sacked as head coach after just one win in 14 games in the 2019 USL Championship season. Independence President and Managing Partner Jim McPhilliamy thanked McGuinness for improving the club "in many ways, including bringing talent to our roster and instituting new training methodologies", and blamed the club's hierarchy, saying they wanted to keep some of his training methods in the future. Galway Football In October 2020, McGuinness was seen taking charge of a training session for the Galway football team. He later stated it was a once off session that happened as a result of being asked by Galway manager