Speaking about his move to the club, he said: “I can’t wait to join my teammates and play my part in helping the club be successful.
“I feel good. It’s a dream to play for United.
“I know I can learn so much from the players here and I can’t wait to play with them”
Büttner will wear the number 28 squad shirt, the same number that Phil Jones was given upon his arrival at the club.
The tenacious defender finally ends a summer long cry from fans for a left back to be brought into the squad as cover for the now unreliable Patrice Evra who, despite only missing three games in three seasons, has become a liability for the United defence.