The Belgian midfielder, who has made 18 appearances for Cagliari this term, had been linked with AC Milan, Juventus, Napoli and Inter, but he is now set to sign for the Giallorossi
The Belgian has made 18 appearances and scored two goals in all competitions for Sardinians this season and his influential performances have put him on the radar of many of Serie A's top clubs.
However, despite the alleged interest of AC Milan, Napoli, Juventus and Inter, the 25-year-old is set to join the Giallorossi.
“I will not get into the merits of the move,” Salerno told Tele Radio Stereo. “That does not seem right.
“But Roma were quicker; that is it. He is going to a top club with a great team."
Salerno is in no doubt that Nainggolan has the quality to prove a huge hit at the Stadio Olimpico.
“Radja has the qualities to do well," he said. “How would I describe Nainggolan? He is a player that can do well anywhere.”
Roma currently sit second in Serie A, eight points behind league leaders Juventus, whom they were beaten by in Turin on Sunday night.