Former Real Madrid president Ramon Calderon believes it would be a mistake for Los Blancos to swap Gareth Bale for Paul Pogba.
Bale was heavily tipped to leave the Spanish giants before the start of the season, but the club reportedly blocked a move to the Chinese Super League.
Pogba was in the same boat at United after he publically admitted to wanting a new challenge during pre-season, but the Red Devils had no intentions of selling the 2018 World Cup winner.
Bale continues to be linked with a return to the English Premier League, but Calderon feels the Welshman is key player for Los Blancos when full fit.
“There are no real players available for good teams like Real Madrid and Barcelona," he told TalkSPORT.
“They are talking here about a swap – Bale or James [Rodriguez] for Pogba. But I think they are only rumours.
"It is true Zidane is looking for having Pogba; for a long time he has said that publicly.
“But I think it would be a mistake, especially to let Bale go. If he is fit and motivated, I think he is irreplaceable for us.”