Jackson has offered the playmaker a third and final contract to remain at Sincil Bank, but with a number of Championship clubs reported to be watching him, Jackson accepts that the 21-year-old's future could be decided at a tribunal.
"Dany N'Guessan has a third offer to be one of the top paid players that this club will ever pay," Jackson told his club's official website. "He's a very special player.
"His standards have dropped a little bit but the standard of the clubs watching him have not. He'll have no problem getting fixed up."
Jackson also admitted that Lee Beevers has paid the price for playing a "dangerous game" after being given a free transfer following his refusal to sign a new deal, although the former Huddersfield boss insists the contract offer is still on the table.
The club's goalkeeping coach, 40-year-old Paul Musslewhite, will also become the club's number two keeper next season following the decision to release Ayden Duffy.