Smalling has been the subject of transfer speculation this week after reports emerged linking him with a £12m move to Arsenal.
After a stop start first half of the campaign, the defender is improving and he was superb in the wins over Tottenham Hotspur and Liverpool in recent weeks.
Smalling’s form is said to have sparked renewed interest from Arsene Wenger after the Gunners tried and failed to sign the 25-year-old last summer.
Although United are keen on adding to their defensive options themselves, they have ruled out selling Smalling.
Fans will be happy to hear of United’s stance as Smalling is establishing himself as a vital part of Louis van Gaal’s side. The Dutchman has helped a number of his players improve and Smalling has really kicked on under his guidance.