Ander Herrera has revealed he left Manchester United because of a difference of opinion over his role in Ole Gunnar Solskjaer's plans.
The 29-year-old Spaniard signed for Paris St Germain on a free transfer earlier this month after five years at Old Trafford.
Asked why he left, Herrera told Spanish newspaper Marca: "I do not like looking at the past very much, but there were differences regarding the project and my importance within it.
"I was very happy, I have a lot to thank the club and the fans for it and also Solskjaer. He did a lot for me to stay, but things did not happen, they arrived late, and by then I had already made the decision to play in Paris."
Herrera's former United team-mate David De Gea has repeatedly been linked with a move to PSG in recent years.
But Herrera was coy when asked about the possibility, citing the quality of PSG's goalkeepers Alphonse Areola and Kevin Trapp.
He said: "David is my friend, I have a great relationship with him and, of course, he is one of the best in the world, for me top three. But here there are already two great goalkeepers."
Herrera's arrival in Paris coincided with continuing speculation over the futures of Kylian Mbappe and Neymar, but asked if he expected both to stay next season, he replied: "Yes, I believe it."
World Cup winner Mbappe is currently one of the hottest properties in the game but Herrera knows the 20-year-old France forward has a way to go to reach the standard set by Cristiano Ronaldo and Lionel Messi.
He said: "One of the things that I admire in Messi and Cristiano is continuity, reliability year after year. That is very difficult and they are always decisive.
"Mbappe has everything to make it so, but time will tell if he manages to maintain that regularity."