The Championships bottom club have already recruited El Hadji-Diouf, Herita Ilunga and Pascal Chimbonda since Willie McKay was appointed club's transfer advisor.
Yesterday they signed Marc-Antoine Fortune form West Brom and Blackburn's Herold Goulon both on short term loan deals.
Agent McKay said “We’ve spoken to Bolo. He played for Celtic in a friendly against St Johnstone. I’m a Celtic fan myself and I was told he was outstanding. But he couldn’t agree anything there and we’ve been in contact with him.”
The 35 year old former Dutch International rejected a new deal at Sunderland and his since found finding a new club difficult.