"I was looking to produce even more results. I was injured and I felt things didn't go well easily. I had a lot of conflict, frustration and worries. In that sense, I think it has been a profound year.
"Honestly, I haven't contributed as much as I did at Dortmund. I was even injured. I still don't quite have that feeling of accomplishment."
Not the words you'd expect to hear from somebody who had just had a Premier League winners' medal hung around his neck, having scored six times and contributed three assists in just 17 starts, but such is the standards that Shinji Kagawa has set himself.
The 24-year-old arrived at Old Trafford last summer with a growing reputation. He had been named in the Bundesliga Team of the Season twice - a deserved recognition for his contribution to Borussia Dortmund's domestic domination.
As United supporters jumped onto YouTube to watch their latest addition in action, he was quickly identified as the creative spark that the Red Devils had lacked during the previous campaign. For a number of reasons, though, it was a rocky start to what had been viewed as the perfect marriage.
Sure, there were glimpses of the Japanese international's ability - he was the only bright light in a disappointing opening day performance at Everton, while a hat-trick at home against Norwich City saw him link up dangerously with both Robin van Persie and Wayne Rooney.
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But injuries, coupled with failing to land a regular position in the side (he played left, right, through the middle and behind the striker - in fact, you name an attacking slot and the pint-sized midfielder probably played there at some point) resulted in Kagawa's United career not taking off in the way that he had hoped.
Even so, former United full-back Gary Neville still believes that he saw enough from Kagawa to know that he will prove to be a smart acquisition. "He will be better next season. Towards the end of this season he showed glimpses of what he could do. He is an intelligent player with good energy, he can spot a run and his own runs are excellent," Neville recently told the club's official website.
"He is tidy on the ball, he can get out of tight situations and I think we will see more of a goalscoring influence and a final-third impact next season."
Now, anyone who watched Kagawa in action for Japan at the Confederations Cup three days ago will have seen the player that Neville had described.
He ended the encounter having had more touches of the ball than any other player (103) on the pitch and had a pass success rate of 85% from his 80 attempts. Yes, the likes of Xavi and Andres Iniesta would probably look down on such statistics, but don't forget, Kagawa was part of Japan team that was facing four-time World Cup winners Italy. Add to that the fact that he scored a smart volley and it can be considered as great work.
Earlier in the tournament Kagawa's threat had been non-existent as coach Alberto Zaccheroni - as he would later admit - got his tactics all wrong against hosts Brazil. Kagawa and Japan were a different animal against the Azzurri, though. They may have lost 4-3, but player and nation did themselves proud.
Why, though, had Kagawa been so effective? After all, he looked like the footballer who had terrorised Bundesliga defences for two years. The impulse answer is: He's a good player who had a good game - simple. Perhaps, but dig a little deeper, and another reason becomes apparent.
Against Italy, Kagawa started wide on the left - not his preferred role. However, it soon became clear that he had been handed a licence by Zaccheroni to cut inside whenever he saw it fit to do so. It was enough to give right-back Christian Maggio a problem - the Napoli man is probably still suffering with nightmares now.
With Maggio being pulled every which way but loose, Japan's left-back, Yuto Nagatomo of Inter Milan, had the freedom of the left-hand side of the park. His willingness to make lung-bursting and enthusiastic darts from back to front meant that there was no need for Kagawa to stand out on the touchline getting chalk on his Adidas's. In layman's terms, the Inter man allowed Kagawa to do whatever he wanted.
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Everton supporters who stayed up until the wee hours to watch that clash will have been nodding in appreciation - they have seen such a relationship blossom over the years at Goodison Park - one that, perhaps crucially, has been moulded by now Man United manager David Moyes.
Is there a better left-sided partnership in the Premier League than Leighton Baines and Steven Pienaar? Actually, extend that to European football? Maybe some of the elite clubs will argue their case, but there are not many.
Such is the telepathic understanding between the pair that this from a couple of paragraphs up "His willingness to make lung-bursting and enthusiastic darts from back to front meant that there was no need for...to stand out on the touchline getting chalk on his Adidas's" could have been written about the two Everton players. Heck, Pienaar even wears Adidas boots!
Moyes will remember only too well the display that Baines and Pienaar put in against Newcastle United at the Goodison last season. They gave Sylvain Marveaux a torrid time - so much so that visiting manager Alan Pardew hauled him off at half-time. They went on to end the campaign with 11 assists between them.
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That's the key point to relationships such as the ones shared by Baines/Pienaar and Kagawa/Nagatomo - they force the opposition to change their tactics and style, thus bringing them out of the comfort zones. Fans of United will be able to fondly recall the times that David Beckham and his partner in crime Neville created chance after chance for the likes of Dwight Yorke and Andy Cole.
The current left-back at Old Trafford is Patrice Evra, who despite having his best return in terms of goals last term, is on the decline. He may still be a threat going forward, but there doesn't appear to be the same willingness, or maybe even capability, to get back and he is often caught out of position. Time and again opposition managers seem to have identified the Frenchman as a weakness in the United rearguard, and not just for his lack of height.
At 28, Baines is in his prime. He's arguably England's best left-back now and despite his loyalty to Everton, would probably jump at the chance to reunite himself with Moyes at United.
It's a transfer that could also help Kagawa to finally settle and produce his best form on a weekly basis. He may prefer to operate in the number 10 role, but with Rooney looking increasingly likely to stay put, perhaps a link-up with Baines would provide a happy medium. As good and as important that Nagatomo and Pienaar are to their respective clubs and nations, United would be merging the cream of the two partnerships.
So, while the rumour mill may be getting all those connected with the champions giddy about Thiago Alcantara or a return for Cristiano Ronaldo, an quietly-spoken Englishman just 40-odd miles down the road in Liverpool could prove the key to United getting the very best out of one of their most talented footballers. It may be the best signing that Moyes makes this summer.