Manchester United midfielder Shinji Kagawa has admitted that he needs to improve his strength if he is to avoid any further injuries.

Kagawa suffered a back injury while on international duty with Japan and concedes that a lack of upper body strength could be a factor.

The 23-year-old said: "I've realised that I need to limber up and strengthen my body.

"There are some tough games coming up. This injury may be due to travel and fatigue but I can get by if I take good care of my body."

Kagawa has revealed that he is still suffering back pain ahead of Saturday's clash with Wigan Athletic.