After Antonio Valencia won the 2012 accolade, the field is wide open with so many players making positive contributions to the campaign.
Old Trafford legend Robson thinks Robin van Persie, Michael Carrick and Rafael all have a good shout of lifting the trophy in May.
"In my mind, there are three players right up there in the reckoning," he told United Review. "Obviously, the way Robin van Persie has come into the club from Arsenal and the way he has played makes him a strong candidate, but I believe Michael Carrick and Rafael are both running him very close.
"Michael has had a great season and it speaks volumes that Sir Alex has played him in more or less all our games. He is a very intelligent footballer and has done excellently all season. Rafael has really progressed and has had a great campaign as well, so it’s a close call between those three, for me."