The Argentine goalkeeper is believed to be attracting interest from a number of European clubs after starring in his homeland.
The 21-year-old has become a first team regular at Estudiantes and has broken records for consecutive clean sheets and minutes without conceding a goal.
His exploits have been noted by the likes of City and Porto, and they are exploring the possibility of putting a deal in place.
City are said to be looking at reaching an agreement for Rulli, bringing him onto their books and then letting him link up with a New York-based MLS team they are to launch in partnership with the New York Yankees in 2015.
They may, however, face difficulties getting a deal put in place as Rulli has no desire to embark on a new adventure any time soon.
On reports suggesting he could soon be snapped up by a top European side, the promising shot-stopper said: "I am not desperate for a transfer at this moment."