Premier League sides Charlton Athletic and Sheffield Wednesday have been linked with the youngster.
"We will do what is best for us, if that means going to a tribunal in the summer and keeping him here until the end of the season then we will," said Gradi, the longest-serving boss in the Football League.
"It will depend on what happens in January and if any decent offers are made - I have a valuation in mind as to what he is worth."