Edwin van der Sar warned David de Gea of a possible return to Manchester United.
The former United post was linked to the director of the football post at Old Trafford, but has not commented on the talks with the club.
But while United tries to hire a football director, De Gea is again giving the club a headache by signing a new long-term contract.
De Gea and United have signed a contract worth £ 350,000 per week, but the Spaniard has not yet reached an agreement.
Van der Sar was once the man between the clubs for United and believes that there are many goalkeepers who could replace De Gea.
"The decision has to be made at some point," Van der Sar said about De Gea.
"It takes a long time, so it's a case of 'yes' or 'no', but I'm not a director of United.
Also other goalkeepers can fill the gap. In the club play some goalkeepers of the Premier League, who can also ascend.
"I was 34 when I joined United. So there are many possibilities. "
United decided to comply with De Gea's high wage demands, although his form had declined in the last year.
De Gea's contract expires next summer and Paris Saint-Germain and Real Madrid have shown interest in signing the 28-year-old.
The goalkeeper could become the top earner of the Premier League when signing the new deal and Van der Sar refuses to worry that United will invest in a relegated player.
When asked whether De Gea's latest form was causing concern, Van der Sar responded: "No. That happened to me, it happened to Ryan Giggs, too.
"Their shape is different. It has been at such a high level for so long that it is noticed at some point, maybe not the first two times, but then people start writing about it. But he will be fine. He is a great goalkeeper. "
Van der Sar, who is currently managing director of Ajax, rejected speculation about his own future when he was directly asked to return to United.
He said, "You never know. At the moment, Ajax is the main idea into which I put all my time and effort and whatever happens in the future, we'll see. "