Barcelona are currently on course to let Robert Lewandowski leave for free when his contract expires at the end of June, as he prepares to turn 38 years old.
The Poland international has bagged 716 goals in 1,029 professional appearances throughout his career, including 17 finishes and four assists in 41 appearances this campaign.
According to Marca, Lewandowski is facing a major decision over his future as the striker is offered a reduced salary at the side in what is the only way he can stay with the Spanish side.
MAN and The Mirror report that United could be interested in snapping up the striker, especially if he does leave for free once the campaign is over.
Lewandowski came close to signing for the side earlier in his career, a move he admits he agreed to.
"To Manchester United I decided and said yes," he told BBC Sport last year. "I wanted to join Manchester United, to see Alex Ferguson.
"They (Dortmund) could not sell me because they knew if I stayed they could earn more money, and that I could wait maybe one or two more years. But it is true that I said yes to Manchester United."
The Express reports that as the striker will miss the World Cup, he could have a full preseason under Carrick ahead of the new season as he builds an attack that can not only rotate for Europe but also compete for the title.
However, he is believed to earn somewhere in the region of £400,000 and £500,000 a week, which could mean he would take a pay cut if a move is agreed.