Flo, who was dropped from the Norway squad for the international friendly with Scotland on Wednesday night, has expressed an interest in moving to either Italy or Spain should the Black Cats wish to cash in on the £6.75 signing from Rangers..
"Siena will make a formal approach to Sunderland on Thursday or Friday," Flo's agent, Gunnar Martin Kjenner, told NRK public television.
"Tore Andre has a positive impression of Siena."