Japan midfielder Shinji Kagawa was unfazed by new Manchester United manager Louis van Gaal's appointment as he and the players had known the Dutchman would take over at Old Trafford next season.

"We've known for some time it was going to be him," Kagawa said on Wednesday after Japan's first training session in Kagoshima Prefecture for the World Cup.

"We've got the World Cup first so I'll deal with all that after this is over."