Sunderland are believed to have made an enquiry regarding Leeds United goalkeeper Andy Lonergan.
The 34-year-old moved to Elland Road in the summer after Rob Green left the club but is second choice behind Felix Wiedwald.
The former Preston North End goalkeeper is well known to Chris Coleman's assistant Kit Symons, with Lonergan establishing himself as number one during the 46-year-old's time in charge of Fulham.
Leeds are not keen to sell and would only consider a deal if a replacement is signed. They would also want a fee for Lonergan who still has 18 months left on his contract.
Sunderland are open to the idea of bolstering their goalkeeping ranks this month after the departure of third choice Mika earlier this month. Youngster Max Stryjek has returned from a loan at Accrington Stanley but could leave on a short-term basis again.
However, Robbin Ruiter has established himself as number one under Coleman, who has been pleased with his progression, and has kept five clean sheets in the 11 games since the former Wales boss took charge.
Bolstering the club's attacking ranks remains the main priority this month though additions in other positions are possible.