Berg has been impressed by Kagawa's positional play.
“I was very impressed with Kagawa [against Galatasaray],” he told talkSPORT. “He looks a top player and is a real bundle of energy.
“His positional play in that role gives Man United something extra. They’ve not had someone in that role before.
“The only thing missing is someone to score all the chances he makes.
"Kagawa gives Man United an extra dimension. His positional sense is excellent both offensively and defensively. He’s always available to get on the ball. It’s easy for Paul Scholes and Michael Carrick to find him."