'Disrespectful': Benfica slam Fernandez approach amid Chelsea interest
"There is a club who want our player," Schmidt said, without naming Chelsea.
"They know that we don't want to sell the player, they try to get the player on their side" with "a lot of money".
Fernandez, who joined Benfica from River Plate in the summer has a £106m buy-out clause in his contract, and Schmidt said the bidding club was trying to avoid paying that.
"To make the player crazy and then to pretend they can pay the clause, and later they want to negotiate.
"They try to get the player on their side. It's disrespectful against all of us, against Benfica and I cannot accept what they are doing.
"There is a lot of money on the table. It confuses you a little bit," Schmidt said of the player who has missed training in an extended stay in Argentina.
The 21-year-old was voted best young player at the World Cup after breaking into the side out in Qatar.
Chelsea have been struggling this season under new chairman Todd Boehly and co-controlling owner Behdad Eghbali.
The club sit 10th in the Premier League, ten points off fourth placed Man United at the halfway stage of the season.
The Londoners bought France international defender Benoit Badiashile from Ligue 1 side Monaco on Thursday.
