Central defender Smalling will turn his attention back to club duties after impressing in England's World Cup qualifiers with San Marino and then Tuesday night's 1-1 draw in Montenegro.
United take on Sunderland at the Stadium Of Light on Saturday - the scene of despair last May after Manchester City scored two late goals against QPR to pip them for the title. And Smalling said: "The way we lost title at Sunderland has been a motivating force all of this season."
He added: "Even when we've been a goal behind, there have been a lot of comebacks to get things from games.
"I think people have been looking back at last season and you don't want to experience that feeling again. I think it has shown throughout the whole season so far.
"It was one of those situations, going into the Sunderland game, where we didn't think we had a chance. But to get so close in the end to winning the title, makes it even worse.
"I wasn't involved that day because I got injured in the previous game against Swansea so, if anything, it was a double blow."
Smalling is hoping to make an impact with United, who play two matches in three days with an FA Cup replay at Chelsea on Monday following on from the Sunderland clash.
He said: "We've got Saturday-Monday, and there are a lot of games coming up. Now that I'm back playing (after injury), I hope to make an impact and keep the season going.
"They are two big games, one in the league and one in the cup, and could go a long way to deciding those competitions."
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