Cristiano Ronaldo says his Real Madrid future remains uncertain. The Portugal international is out of contract in 2015 and speculation over a possible return to Manchester United continues to dog the forward.

Talk over an extension is ongoing and club president Florentino Perez claims he is confident of an agreement with the Portuguese. However, the player himself is less certain, although he has refused to comment one way or the other.

Cristiano Ronaldo

"... still not resolved this [contract] situation and I do not talk about it because it is not the right time. Later maybe going to know something more concrete, but now I just train and work [responsibly]," he told Spanish newspaper AS.

Ronaldo's situation at the Santiago Bernabeu came into sharp relief late last year, after comments about being unhappy in the Spanish capital led to talk of a Premier League return. Since then, speculation over a new contract and Madrid's pursuit of Tottenham winger Gareth Bale have fed the rumour mills as well, with the club claiming they can make a big-money bid for the 28-year-old.

Meanwhile, former United defender Denis Irwin thinks Moyes could convince Ronaldo to return this summer. The 47-year-old Irishman thinks the Spaniard's pursuit of Bale could be key in deciding Ronaldo's future.

"Manchester United have been linked for a second time this summer with a return to Old Trafford for Cristiano Ronaldo. Of course it could happen, but I believe the speculation may be sparked by the ever-clearer indications that Gareth Bale is on the way from Spurs to Real Madrid," Irwin explained.

"Can Real Madrid, rich and all as they are, afford to buy and then pay that brilliant pair of players? If the answer is yes, then Madrid see them as their answer to the [Lionel] Messi and Neymar duo at Barcelona. If the answer is no, then Ronaldo will be allowed leave, and Manchester United is an obvious destination," he concluded.