Everton have confirmed they will be without Jean Philippe-Gbamin for at least eight weeks.
The summer signing from Mainz injured his thigh prior to Friday's loss to Aston Villa.
A club statement read: "Everton Football Club can confirm that Jean-Philippe Gbamin has sustained a tendon injury in his right quadriceps muscle, which will keep the midfielder out of action for at least eight weeks.
"The full timescale for the injury will be established following further investigations this week.
"The Club are in communication with leading experts around Europe to ensure the optimal outcome."