Shinji Kagawa admits he failed to live up to expectation following his move to Manchester United 18 months ago, but believes he is just one goal away from turning that around.

The Japan international was unavailable for United's 1-0 defeat to Newcastle at Old Trafford on Saturday under bizarre circumstances, after he was forced to have his stomach pumped after eating too much.

It was another stumbling block for the Japan international who had in recent weeks begun to feature more regularly in David Moyes' starting XI. Following his £12m switch from Borussia Dortmund last summer, Kagawa's first six months at the club were largely plagued by injury and inconsistency, which left the playmaker unsatisfied with his contribution to United'2 20th league title.

"Getting injured early on last season was sad and disappointing," Kagawa told United Review. "After my transfer I was very aware of people's expectations but I couldn't meet them, which was frustrating.

"Later in the season I got some chances to play and by then I was more accustomed to the team and my environment so I played much better than I had in the first half of the campaign although I wasn't 100 per cent satisfied overall.

"This season I want to improve my performances and make this season better than the last. Even though I haven't yet scored this season, I believe one goal will give me confidence and set me on my way."

Having flourished in a central position for Dortmund, Kagawa has seldom been afforded starting berths in his preferred position at Old Trafford, although Moyes has deployed the Japan international in that position in Champions League ties this season.

Often used in a left wing position, Kagawa himself insists he must become more flexible over the course of the season.

"I played behind the main striker at Dortmund but I usually play on the left with Japan, and I also took this role at Cerezo Osaka," he added.

"I have some experience out wide but I think I should be flexible enough to play in a number of roles, so I'm a more attractive player to the team and can contribute even more

" Every day I'm learning how to trouble my opponents on the left, how best to cause them problems with my movement, but I'd still like to be capable of taking up more positions."