Sandomierski's club have told Celtic they have permission to field the keeper, although they want to know what the Glasgow giants are offering in return for his signature.
"We have received a request for Grzegorz from Celtic," the club's chief executive Cezary Kulesza told sports.pl.
"We have replied that Grzegorz may appear in Scotland on trial, but provided that we hear first what their transfer proposal may be.
"We are waiting for a response. Grzegorz had trials at Everton and we are also waiting for a concrete offer from them."