The Russian-born businessman said he is impressed with his new manager, who was appointed on Friday within a couple of hours of the sacking of Csaba Laszlo.
"He is an expert I have wanted to get into my team for a long time," Romanov said of the former Hearts' captain.
"I hope he is going to stay with us for a long time.
"He had a very good reputation working for Hearts in the past.
"I talked to him and realised that this man is prepared to fight against the Scottish football mafia to the end."
Romanov stressed that Jefferies was his personal choice after sacking Laszlo, despite his reluctance earlier to appoint Scottish managers.