Everton defender Luke Garbutt will visit a specialist on Thursday to undergo an assessment on damaged ankle ligaments.
The 19-year-old left-back returned from a two-month injury lay-off in Monday's Under-21 defeat to Blackburn but could now face another stint on the sidelines.
Thursday's tests will seek to ascertain the extent of the damage and the likely length of absence.
An England Under-19 international, Garbutt made his Everton first-team debut in August's 5-0 League Cup victory over Leyton Orient.
That followed a successful loan spell at Chelteham Town last season during which he made 37 appearances for the League Two outfit, scoring two goals.