The Nottingham Forest says the Romanian shot-stopper spent the last four months of the season at Forest, keeping six clean sheets in his 13 Championship appearances.
And he is nearing a return with the two clubs agreeing to the move for the 31-year-old go.
The only stumbling block has been over wages, with Pantilimon wanting significantly more than Forest are prepared to pay.
There is also a sense of urgency for Forest to bring in the former Manchester City man.
City Ground boss Aitor Karanka wants a new keeper before his side head to their pre-season training camp on July 10.