Udinese have told Gokhan Inler to accept a switch to Napoli or prepare himself for a Stadio Friuli return.
The two clubs have agreed terms over a transfer fee for the midfielder, but Napoli have yet to reach a compromise with his agent.
Inler is understood to be considering his options given an interest from Juventus, but Udinese say they won't do a deal with any other club apart from Napoli.
"I don't know what has occurred," Udinese owner Gianpaolo Pozzo told Radio Kiss Kiss on Thursday.
"We agreed everything with Napoli a month ago, while his agent and the player himself are serious people.
"I don't know what the delay is, but we are not prepared to lose any other time with any other clubs.
"If they agree things with Napoli then that is fine, otherwise we'll be just as happy to have him back with us for our Champions League campaign next season.
"I wouldn't be too pessimistic about it. Things are at an advanced stage with Napoli and if Inler goes then he will spend the rest of his career there."