Chelsea boss Frank Lampard appreciated his one season with Manchester City.
Chelsea meet City on Saturday evening.
Looking back on how pivotal those 12 months at City under Manuel Pellegrini were in where he is now, Lampard said: "The year in Manchester, in terms of what I'm doing here now, was perfect for me because it opened my eyes to another club, another structure, another dressing-room, another coaching philosophy, another idea.
"And then at New York, again that continued and that starts to shape what you're thinking next.
"At the time I was trying to look around me more and see things from a different side, which was less as a player and more about how I'd work with people around me.
"I can't look back on my career now with any negative feelings even about leaving Chelsea now. I just look back with a thankful feeling that I had such a long career at great places."
