Irving Scholar, Forest's football consultant, will fly to the Netherlands today to try and persuade the striker to return to the club.
Forest are refusing to sanction Van Hooijdonk's transfer request and the Dutchman has steadfastly refused to return to Nottingham for pre-season training.
David Unsworth's transfer saga has taken another twist, with Aston Villa threatening to stop his wages if he fails to rejoin them this morning.
Unsworth has been ordered to report for training at Villa's Bodymoor Heath headquarters after Everton failed to meet Friday's deadline for settling his pounds 3m transfer fee to Goodison Park.
Unsworth, however, is threatening to ignore Villa's instruction and remain at home in Liverpool, which could force the Villa manager, John Gregory, to call in the Football Association and Professional Footballers' Association to try to resolve a situation which even the player's agent admits has become a "complete farce".
Villa's secretary, Steve Stride, said: "The lad has a career and he needs to think about that. The situation is clear. He is still our player and if he doesn't turn up then he will be fined. The maximum we can fine him is two weeks' wages.
"But if he doesn't train or play for us he won't be paid either. I would hope that if he is thinking about not coming back he has a change of heart. If he doesn't, I wouldn't like to say what will happen long term."
Gary Mabbutt has been forced to put on hold his comeback because he needs a knee operation. The former Tottenham captain is hoping to relaunch his career after being released from White Hart Lane club earlier this summer.
Fulham have expressed an interest in signing Mabbutt, but he has postponed talks until next month, by when he hopes to have recovered.Reuse content