Sir Alex Ferguson believes that the January arrival of Juan Mata from Chelsea ended any chance that Shinji Kagawa had of succeeding at Manchester United.

Ferguson signed the Japanese international from Borussia Dortmund during the summer of 2012, but following the Scot's retirement a year later, Kagawa struggled to force his way into new manager David Moyes's starting lineup on a regular basis.

Moyes recruited Mata for a then club-record £37m during the winter window, which lessened Kagawa's opportunities further and when he struggled to establish himself under Moyes's replacement Louis van Gaal during the early parts of this season, the 25-year-old returned to Dortmund.

Speaking about the situation, Ferguson told Bild: Shinji is back in the environment in which he feels right. He has, with (Jurgen) Klopp, a coach who gives him the necessary self-confidence.

"I was very pleased with Shinji. He had settled in well with me, and I also had the feeling that he felt comfortable with us. Every coach has his own philosophy. As Moyes preferred Mata, Kagawa has felt that he is no longer first choice and was a bit resigned."

Kagawa has found the net once since he rejoined the Bundesliga outfit.