The Senegal international swapped French Ligue 1 club Rennes for Premier League giants Chelsea for a fee in the region of £22m in the transfer window.
Mendy has made a solid start to life in England, keeping a clean sheet in each of his six appearances in the top flight and the Champions League, including one against former employers Rennes.
Former Manchester City star De Jong is impressed by the Blues’ new goalkeeper and has hailed the confidence that he has while standing in goal.
The Dutchman feels the presence of Mendy will give the Chelsea defence confidence and expects manager Frank Lampard to be pleased with the custodian.
“The boy just doesn’t want to let a goal in, does he?“, De Jong said on beIN SPORTS.
“He looks the part though, the way how he is standing in goal, the authority that he has, the confidence that he has.
“It is good for the defence of Chelsea to know that they have got such a great goalkeeper behind them.
“I think Lampard can be very, very pleased to have a goalkeeper like him.“
Having made an impressive start to his Chelsea career, Mendy will be hopeful of keeping his momentum going.