The 26 year old has started the last five games for the Red Devils, after shaking off a troubling tendonitis injury.
"I've known a lot of the players for a long time through the England set-up and, of course, the national team has trained at Carrington on numerous occasions and also played at Old Trafford. So it's always been familiar to me.
"Being a United player is everything I expected and more. I've been really impressed with the club as an organisation, the people, the way everyone has taken to me. I've been hugely impressed with the quality of the players, the staff, the fans and also the style of football this team plays.
"The only disappointment has been that I'd like to have played more games. Hopefully that will change now."