Toffees midfielder Cleverley suffered a potentially serious ankle injury during the 0-0 draw against Tottenham Hotspur on Saturday following a strong challenge from Spurs' defender Dier.
Cleverley is suspected to have suffered ankle ligament damage but Everton manager Martinez has refused to point any finger at Dier for the injury.
Martinez told the Liverpool Echo: "It was an unfortunate action, when Eric Dier went with all the power and the strength of the world. He gets the ball and it's unfortunate that he gets Tom's leg, it wasn't malicious, it was a nothing challenge. It was very fair.
"We don't know [how long] yet, he'll be out for a period, but Tom is so fit, any other player would have broken his leg there. So maybe with a little bit shorter period he'll be back on the pitch."