Jonny Evans has been impressed by new Manchester United teammate Alexander Buttner.
The pair featured in the U21's victory over Tottenham.
"He's been training all week with us and I've been very impressed," the 24-year-old said. "He seems very confident on the ball, good in the tackle.
"He probably didn't get as much of the ball as he would have liked. But he defended really well, which is important, and I'm sure he can be happy with himself."