New Manchester United signing Shinji Kagawa says he'll leave his shirt number up to manager Sir Alex Ferguson.

Kagawa admits he discussed the No7 shirt with officials during his whistlestop medical.

"We did [discuss it] but nothing will be confirmed until Sir Alex comes back," Kagawa explained. "Since I am very new to the club, I have no intention to get an important number. Let's wait and see how it goes.

"I just told them my hope because I didn't know which numbers are available.

"Having completed the transfer, I can't think anything negative anymore. I feel positive. I would like to achieve big things with such a big, historical club. I know there's a tough challenge ahead of me but I am excited to have the chance to take it."