Shinji Kagawa is ready to hit the gym to be a success at Manchester United.

Kagawa, 23, signed by Manchester United for £12million from Borussia Dortmund, admits he is going to face a gruelling baptism of fire in the first few months of his new life.

Kagawa, who scored his first United goal in Wednesday's 1-0 win over Shanghai Shenhua, said: "It's going to be a tough league to play in. Of course I will adapt to it, even if it means going to the gym more often."