The Uruguay international is under contract with Porto until the summer of 2016 and is valued at around €30million (£23.8m).
However, he has reportedly attracted the interest of a number of leading European clubs, including Chelsea, Tottenham and Liverpool.
Paris St Germain, Napoli and Juventus have also been linked with the 26-year-old, whose representative believes a departure from Porto could happen.
Flavio Perchmen told Antena 1: “I spoke with Alvaro last week and he is calm. We are waiting to find out if there is any offer.
“We think everything will go well and that he can leave the club, but right now we do not have any concrete offer.”