This is according to ex-Chelsea man and pundit Cascarino.
De Gea was at fault for 2 of Everton’s 3 goals last Saturday.
Speaking to talkSPORT, Tony Cascarino said: “David De Gea for the first goal has got to do better. Third goal, you’ve got a licence as a goalkeeper. Sometimes you can be reckless, you can come out and charge, you’ll get protected.
“De Gea took the option of actually being quite safe and just making the minimal amount of effort to spread his body and make it difficult. Look, Manchester United are going to be ruing that 3-3 draw.
“And De Gea, as much as we keep going back, you’re paid a hell of a lot of money at a big football club, you do not survive playing averagely. And De Gea has been average for 18 months.”
The Toffees scored an equaliser from the set-piece with their last kick of the game at Old Trafford on Saturday with the Spaniard failing to clear the ball.
De Gea has now saved just 60.9% of the shots on goal in the Premier League this season, the second-worst save percentage for any goalkeeper.