Crystal Palace boss Ian Holloway says Wilfried Zaha must be loaned back if he is sold this month.
Zaha has been linked with a string of Premier League clubs and reports have claimed that Manchester United are leading the hunt for the 20-year-old.
"Wilfried Zaha is wanted by some of the biggest clubs in the Premier League," Holloway wrote in his Sunday Mirror column. "And THAT, in the football silly season that everyone else calls January, is the problem.
"The need for confidentiality makes it impossible to reveal who is interested in Wilfried and who has made a bid.
"But the constant buzz of speculation is difficult to cope with. It is a great tribute to Wilf himself that he has been able to hang on to his sanity.
"He had a little dip in form when the transfer talk started to get louder last month, but he has since shown that class is permanent.
"I felt it necessary to have a chat with Wilfried this week about what might happen and what definitely won't be happening. Even if we do reach an agreement with a club, it would have to include a clause that Zaha stays put for the rest of the season."