Former Aston Villa defender Ron Vlaar has weighed into the debate around Davy Klaassen's problems at Everton.
The Holland midfielder struggled during his first season in England, having joined Everton last summer from Ajax.
"The step is so great. The intensity is huge. Davy has to do what he feels good about," Vlaar told Algemeen Dagblad
"But it is clear that he will have to arm his body against the violence of the Premier League.
"In the midfield you really have to be able to do everything. Box-to box. Plus the better demolition work. And then also make a difference in a creative way. That is really difficult."