Skysports.com understands Celtic have made an enquiry for Crystal Palace's Julian Speroni.
Speroni is regarded as one of the finest goalkeepers in the Championship and a number of clubs have reportedly been monitoring his situation over the past few months.
Celtic are now believed to have contacted Palace to ask about his availability, as Neil Lennon looks to bolster his options between the posts.
Lukasz Zaluska is currently first choice at Parkhead, following Artur Boruc's departure to Fiorentina earlier in the summer.
If Celtic decide to step up their pursuit of Speroni and table a bid they could face competition from Middlesbrough, who are also thought to be interested.
However, both clubs may find it hard to strike a deal with Palace as George Burley has previously made it clear that he would like to keep the 31-year-old.
Speroni moved to Selhurst Park from Dundee in 2004 after starting his career in his native Argentina.