Everton assistant manager Duncan Ferguson has confirmed Dominic Calvert-Lewin injured his hamstring in the win over Tottenham on Wednesday.
Calvert-Lewin, who scored in the 5-4 victory, had to be withdrawn after 55 minutes.
The England striker is now in doubt to face Fulham this weekend.
"We're not quite sure [yet]," Ferguson said when asked about the extent of the injury.
"He was complaining about his hamstring when he came off the pitch. We've not got an assessment but it does look like a wee bit of a hamstring tweak."
