Everton midfielder Abdoulaye Doucoure has suffered a stress injury to his foot.
The 28-year-old played for 90 minutes in Everton's 1-0 home loss to West Ham on Sunday but the Toffees have confirmed the French midfielder picked up an injury during the Goodison Park clash.
Everton say Doucoure will not require surgery and the club are running tests on the midfielder to discover the extent of the injury.
Doucoure suffered a fractured foot earlier this calendar year and missed seven league matches last season due to the problem, but it is feared he will face longer on the treatment table after this latest setback.