The Portuguese midfielder, 20, spent last season on loan Lille where he made 27 appearances and scored three goals.
Lopes, nicknamed 'Rony' after his idol Ronaldo, made just five appearances for the Blues since joining the club from Benfica in 2011.
He made his debut in January 2013, replacing David Silva in a cup tie against Watford and scoring an injury time goal to become the Club's youngest goal-scorer aged 17 years and nine days old.
A year later he starred in City's 3-0 Capital One Cup win at West Ham, assisting goals for Alavaro Negredo and Sergio Aguero.
Lopes also won the 2012/13 MCFC Academy Player of the Year award and has represented Portugal at every level from Under-16 to Under-21 on 58 occasions in total - this despite being born in Brazil.
Popular with team-mates and staff at City, everybody wishes Marcos great success in the future.
Support the team as they aim to continue the 100% start to the season at our next home match in the Premier League against Watford on Saturday 29th August at 3pm. Make sure you don’t miss out on another memorable game at the newly-expanded Etihad Stadium and buy your tickets now or enjoy the game in the new 93:20 bar from £75.
Hospitality is also available – Experience the new Legends suite from £150 + VAT and enjoy a matchday like a Legend. To book, call our hospitality team on