Enzo Fernandez and the rest of his Benfica team-mates have only one shot at their career, Roger Schmidt has acknowledged, but the coach is not entertaining transfer talk until the New Year.
Fernandez has enjoyed a superb first season in Europe so far, with the Argentina international helping the Lisbon club top the Primeira Liga and their Champions League group, before also tasting World Cup success.
Handed the tournament's Young Player Award for his performances in Qatar, the 21-year-old is expected to be a target for several of Europe's elite in the January transfer window.
Schmidt previously expressed his hope that Fernandez and other Benfica stars who impressed at the World Cup would stay, but acknowledged on Thursday that the desire of the players could prove decisive.
"These young players sometimes have opportunities," he said ahead of Benfica's Primeira Liga clash with Braga. "It's not just Enzo, it's all the players.
"It's part of the football business. If they have opportunities, they have to make decisions. I can give them advice and recommendations.
"But I always respected the players' decisions, because they only have one career."
Fernandez, who only signed for Benfica in June from River Plate, has already been linked with the likes of Real Madrid, Chelsea, Liverpool, Manchester United and Newcastle United.
With the transfer window yet to officially open for business, Schmidt would not entertain further discussion of potential departures from Benfica, adding: "Until December 31, we are safe.
"Nobody can buy a player. On the eve of the game against Braga, I'm just focused on that. Everything else will happen, perhaps, when the transfer window is open."