Smalling has made 19 appearances in all competitions for the Red Devils and he has insisted that he will not get "frustrated" when he is not picked.
"No matter whether you are young or old you want to play in as many games as you can," United's official website quotes him as saying. "When you get your chance, you need to take it. You don't give the manager an excuse to leave you out.
"You're at one of the biggest clubs in the world and the manager needs to do what he does. We are happy at the minute because everyone is getting games. Long may that continue.
"When you are injured you want to play. When you are fit you just want to play every week. But there is a large degree of patience required. You can't get too frustrated."
Smalling joined United from Fulham for £10m in July 2010.