With current number one stopper Edwin van der Sar turning 39 this year, Sir Alex Ferguson will be on the look out for a younger alternative who has a few more years experience than second in command Ben Foster.
According to speculation in El Mundo Deportivo, Old Trafford officials will initiate their approach for 28-year-old Casillas, who is regarded by some as the world's best goalkeeper alongside Gianluigi Buffon, next week.
Ferguson will face a tough task in convincing the Spanish international to leave the Bernabeu who are in the process of re-establishing themselves as the Galacticos side of days gone by.
It is not the first time this year Casillas has been linked with a move to the Premier League. United's neighbouring rivals, Manchester City were prepared to pay £150 million for him in January.
Needless to say the deal was rejected despite the Eastlands club being ready to meet the considerable demands of Casillas' buy-out clause.
Meanwhile, United midfielder Darron Gibson has said the club should worry less about the impact losing Cristiano Ronaldo will have on next season, insisting he will not be missed all that much.
Amazed by the final sum of money paid for the 24-year-old Portuguese winger, Gibson said: "A fee of £80 million was simply too much to refuse. But we've a great squad and I don't think we'll miss him. There are a few that can step in and do as well."