After signing on the dotted line, Trafford said: "Rejoining City is such a special and proud moment both for me and my family. I always dreamed that one day I would be able to come back to Manchester City. This is the place I call home - it's a truly special football club with fantastic people who make it such a unique place to work and play.
"I am also very excited and honoured to have been given the opportunity to work under Pep and with such a world-class group of players. I am still very young and hungry to keep learning and improving - and I know there is no better environment than Manchester City to help make me become the best goalkeeper I can be. I also cannot wait to play in front of the amazing City fans for the first time and will do everything I can to help this great club look to achieve even more success."