Everton striker Dominic Calvert-Lewin is a major doubt for Monday's Merseyside derby at Anfield.
The England international played just over an hour of last weekend's win over Arsenal but afterwards manager Sean Dyche admitted it had been a risk as the player was struggling with a hamstring problem.
That has prevented him from training this week and puts his participation at Anfield in doubt.
'We're still monitoring him. It will be touch and go, at best, I would think,' said Dyche.
'We're hoping it settles down as quickly as possible.