Sean Dyche says Dominic Calvert-Lewin faces a dual challenge of getting over his hamstring issue and becoming "genuinely fit so his body doesn't break down".
The Blues striker was absent from the matchday squad for the Merseyside derby after playing an hour in Dyche's first game against Arsenal. He had been described as "touch and go" in the build-up to the fixture but missed out with academy graduate Ellis Simms starting in his place.
What happens next for Calvert-Lewin is likely to be crucial to Everton's season and the club's Premier League survival hopes but Dyche stressed he will not risk the 25-year-old's long term health by rushing him back.
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Asked how close Calvert-Lewin was to being involved at Anfield, Dyche said after the 2-0 defeat: "He is working diligently, I think he is having an up and down time. The challenge we have got is not just to get the injury fit, it is to get him genuinely fit so his body doesn't break down.
"I think I might have to give him extra time for that and actually slow that down to make sure because we don't want a player for one game, we want a player for as many as possible. That is going to be the right challenge for me and my staff, to make sure we give him the chance to be really fit if you like - rather than sort of getting him back for the sake of one game. So it is a tough call. Hopefully, we will see how it is settling this week."
