Gueret, who recently made his first appearance in two years, has decided to keep his options open rather than sign immediately.
He told the South London Press: "I would love to stay but I need to do what is best for me. I cannot close my eyes to other possibilities.
"If I have to go away to get what I need, I will do so. Both Tony and I have deals that end in the summer which is an unusual situation."
The news comes after loan keeper Andy Marshall admitted this week he was unhappy at being left on the sidelines and with first choice keeper Tony Warner set to leave in the summer too, Wise will need to start looking around for some alternatives to the two stoppers.