An interesting transfer rumour has emerged concerning two top strikers, despite the summer window being months away.

Simply put, Manchester United loanee Radamel Falcao has failed to live up to expectations since making a much-anticipated move to Old Trafford last year.

The 29-year-old Colombian international was unfortunate to miss out on the World Cup due to a knee injury whilst playing for Monaco and since then has struggled to regain the same goal-scoring form whilst at Porto and Atletico Madrid that made him once of the most coveted strikers before ending up with the Ligue 1 side.

Many had expected him, now with one of Europe's biggest clubs to help the Red Devils as they seek to make amends for their poor campaign last season. However, the goals have continued to become hard to come by. As such, it is looking increasingly unlikely that the Premier League powerhouse will exercise their option to fork over £43 million for his services end of the season.

Falcao has not had the impact in England that he himself and fans would have hoped for

With him set for an exit, rumors are rife that it will not be back to Monaco for the player, but rather Spain. Real Madrid were strongly linked with a move for him this past summer, and the player himself seemed to fuel this after quickly deleting a tweet, "Hala Madrid" on Deadline Day.

Although the La Liga giants have the likes of Gareth Bale, Karim Benzema, and of course Cristiano Ronaldo on their payroll, as well as Javier Hernandez on loan, his agent, Jorge Mendes is closely associated with the club and has a good rapport with the 10-time Champions League winners.

Meanwhile, the Red Devils have also been linked with a move for Bayern Munich's Robert Lewandowski. The Polish international has had a solid season in his debut season since departing Borussia Dortmund, but that has not stopped rumours from Germany from speculating that he is not happy under Pep Guardiola.

Given the Spanish tactician's curious relationship with strikers--just think of Zlatan Ibrahimovic, Samuel Eto'o, and most recently Mario Mandzukic--there may be some credence to these whispers, and Lewandowski, who quickly established himself as a top talent with Dortmund, did not have a lack of suitors when he announced he would not stay with die Schwarzgelben.

Robert Lewandowski could be the one to replace Radamel Falcao this summer

£30 million is the figure being bandied about for him and given that Falcao would cost £13 million more, English reports claim that Manchester United certainly would not be opposed to throwing their hat in the ring for him should he become available this summer.