Yerry Mina is expected to be out for 'several' weeks and miss the re-start of the season after injuring his thigh in training.
The 25-year-old has already started rehabilitation on the problem he sustained last week and is said to be making good progress.
Mina underwent scans which revealed he had suffered a partial tear in his left quad and he now faces weeks on the sidelines.
Everton are not putting a timescale on his return but the injury means the Colombian is almost certain to miss the team's first game back, against Liverpool, which is scheduled for June 20.
Mina's injury leaves Carlo Ancelotti with only two fit senior centre-halves in the squad, Mason Holgate and Michael Keane ahead of the Premier League's resumption later this month.
