Buttner recently completed his move to United from Dutch side Vitesse Arnhem.
Evans and Buttner did both featured in Manchester United's 2-1 Under-21 Premier League win over Tottenham on Wednesday evening.
"He's been training all week with us and I've been very impressed," Evans told the club's official website. "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."