The 26-year-old midfielder joined the Giallorossi from the Sardinian side in February of last year as part of a €6.5 million co-ownership deal.
However, following some outstanding performances both domestically and in continental competition the Rossoblu hierarchy now value the second half of Nainggolan’s contract at €15.5 million, while Roma president James Pallotta is unwilling to pay more than €10 million to secure the player’s future at the Stadio Olimpico.
Nainggolan has further fuelled speculation in recent days by revealing to Sky Sport Italia that there is a 50 percent chance that he will remain in Rome beyond June.
It is believed that he wants assurances about his place in a midfield department which also contains Daniele De Rossi, Kevin Strootman, Miralem Pjanic, Alessandro Florenzi and Seydou Keita.
If the Belgian was to leave Roma in the summer a return to Cagliari is highly unlikely with several Premier League side’s, including Liverpool, waiting to see how the current situation is resolved.