Everton manager Roberto Martinez has insisted that James McCarthy's recurring hamstring issue is a "serious problem".

The midfielder returned to action from an injury last weekend, but was substituted just half an hour into last night's Europa League 2-0 win over Wolfsburg in Germany.

"We're going to get him checked today," Martinez told reporters. "The reaction was good from last night but we'll find out exactly what the extent is.

"It's the hamstring that he had a bit of trouble with beforehand and we need to assess it with a lot of intention. It's a serious problem because it's a problem he's had before and we need to make sure we find the root of the problem."

McCarthy is unlikely to feature in this weekend's Premier League match against Tottenham Hotspur.