Manchester United boss Sir Alex Ferguson has revealed that he will be without summer signing Shinji Kagawa for around a month as reported by the Daily Mirror.

Kagawa suffered the knee injury in the first half United’s comeback against Portuguese side Braga in the Champions League on Tuesday night and Ferguson compared the injury to the one that has kept England winger Ashley Young on the sidelines this season.

"Shinji is going to be out for three to four weeks,” Ferguson said.

"Playing on with the injury didn't help the situation for him. He did well to play on.

"It's a knee injury, similar to the one Ashley Young had.

"He'll be out for three to four weeks, which is disappointing for him."

The United boss did have some good news to report though as young defensive pair Chris Smalling and Phil Jones are both ready to start full training after recovering from long term injuries.