After Robin van Persie and Shinji Kagawa netted on their first appearance for the Reds at Old Trafford, the new signings are wasting little time endearing themselves to the home supporters.
"Some of Büttner's play was good but I think he was a little bit rash at times," the manager admitted to MUTV. "He has a great engine and great enthusiasm for the game but he's raw with a lot of rough edges there.
"We think we can develop that and hopefully he can be a really good addition to the team. He scored a lot of goals in Holland and was determined enough to get that goal. It was a little bit lucky, I don't know if it got a deflection or not, but he showed his willingness to get in there and deserved it."
Powell continues to earn plaudits from Sir Alex after taking his impressive training-ground work onto the big stage.
"Nick Powell is going to be a really good player who, we hope, will fill Paul Scholes' boots in terms of he's got terrific vision, good temperament, two great feet, is quick and is a great striker of the ball. For a boy of 18, he's not 19 until next March, it's been a terrific day for him."