The England international has been in good form in Manchester United's recent games.
Smalling has put in several strong performances in recent weeks, playing a key role in the vital victories over Spurs and Liverpool.
It has seen the central defender linked with a return to London, with Arsenal credited with having an interest in bringing Smalling back to his hometown.
The England international was linked with the Gunners in the summer when United were said to be following Thomas Vermaelen's situation at the Emirates very closely.
As it turned out, the Belgian moved to Barcelona and Smalling remained as Old Trafford, where he has made 22 appearances under Louis van Gaal this year, all in his favoured central defensive position rather than at right back where he has often featured under previous United managers.
Speaking at an England press conference on Sunday, Smalling reiterated that he was happy to extend his stay in Manchester beyond 2016, while praising the effect Van Gaal has had on his career.
"I am enjoying it," the former Fulham man said. "I have always enjoyed playing for United, especially at the minute.
"If I can contribute, as now, then I am happy to stay as long as they want me."
When asked if he was playing the best football of his career, the 25-year-old emphasised his confidence by responding: "Yes, I think I am.
"The manager has shown a lot of faith in me. Especially over the last couple of months, I have stayed fit, the manager has chosen me, and I am enjoying my football."