He left United for Hannover half way through last season and has gone on to score 15 goals in 24 appearances for them.
Whilst singing the praises of Manchester United, Diouf recognises he had to leave for the sake of his career.
“Manchester United is a great club and I have enjoyed being a player of the club,” Diouf said. “But when at such a big club like United you need someone that fully believes in your skills. It’s useless just to be one more good player. It is a fact I wanted to move on. I did not want to have another loan spell at another club.”