The Japan international arrived at Old Trafford as a 23-year-old from Borussia Dortmund with a big reputation having helped the club to back-to-back Bundesliga titles.
But he struggled to display his best form for the Red Devils, scoring six goals in 57 games, and was sold back to Dortmund by Louis van Gaal for £6.3m in 2014.
Kagawa is thriving once again at the Westfalenstadion but thinks he would do things differently if given a second chance at United.
“Fight more, every day – even a small player like me should fight every day to succeed at a club like Manchester United and it’s the same now at Dortmund,” he told FourFourTwo.
“I just have to focus on how I can get better every day to try to succeed at this level. Of course, you also have to be mentally strong.
“Fight more, every day – even a small player like me should fight every day to succeed at a club like Manchester United”
Shinji Kagawa
“I was still young, just 24 or 25. I had a lot of experiences there and that helped me grow, and looking back I wasn’t concerned about anything, just focusing on doing the best I could.
“Of course there were good players there but everyone thinks differently; the Dortmund coach is the Dortmund coach, and the Manchester United coach is the Manchester United coach, and I just have to accept how everything went.”