The 28-year-old winger returned to his former club on a season-long loan in August as part of the deal that took Argentine defender Marcos Rojo to Old Trafford.
Nani was allowed to leave United in the off-season following the arrival of Angel Di Maria from Real Madrid, despite the Portugal international having penned a new five-year contract with the club in September last year.
He has won four Premier League titles and the UEFA Champions League with the Red Devils, but injuries and a loss of form over the past two seasons saw him fall out of favour with management.
The Cape Verde-born player has scored five goals in 14 appearances for the Lions this term, and believes he can force his way into Louis van Gaal’s first-team plans.
When asked if his United career could be resurrected, Nani told reporters: “Why not? I went out [to Sporting] to play more and get to my best. If there is an opportunity, we will see.”
Nani returned to the Theatre of Dreams on Tuesday, where he helped A Seleccao to a 1-0 victory over 2014 World Cup finalists Argentina.
However, he hardly endeared himself to those Red Devils fans in attendance after leaving Di Maria clutching his ankle following a strong challenge, although the injury is not thought to be serious.
Commenting on Portugal’s performance, Nani said: “I think it was a very tough game for us but we knew, when we play against a team like that, it is very difficult.
“I think all the players did well. We defended the result but tried to win the game as well and, in the end, we had a bit of pressure and we won the game. It’s great for us.”