As reported by A Bola, Jose Iribarren admitted that reports of interest in his player from Chelsea and United is news to him.
It had been suggested earlier this week that the Manchester United and Chelsea target would be available for transfer.
But Iribarren - speaking to Antenna 1 - confirmed that he's not heard of any bids for his player.
"So far, to me, there is nothing and therefore I cannot speak of a concrete situation.
"There is a market for Nico but it has to be interesting for both parties. He remains at Benfica."
As well as Chelsea and United, defending French champions Paris Saint-Germain have also been mentioned as a potential destination for the Argentinian playmaker.
The 25-year-old attacking midfielder has been with Benfica since 2010, and has made over 87 appearances for the Portuguese club.
He has just six caps for Argentina and is not expected to feature at the World Cup in Brazil next summer.
It seems unlikely that United would move for Gaitan considering their pursuit of Juan Mata looks likely to be successful in the coming days.