Jean-Philippe Gbamin could be out for three months at Everton.
The midfielder, who joined the Toffees from Mainz in a 25million deal earlier this month, missed Friday night's 2-0 defeat at Aston Villa.
After the game, the club confirmed Gbamin had suffered a 'significant' injury to his right quadriceps muscle and that he would be assessed further this week.
However, it has now emerged that the Ivory Coast international may miss nearly a third of the season with the problem he picked up in training, says BBC Sport.
Everton are hopeful that Gbamin will not require surgery and that he could be ready to play again in two months rather than three.
