Muhamed Besic has been ruled out of Everton's opening Premier League game of the season against Watford, reports Sky Sports.
The 22 year old Bosnian suffered a hamstring injury during Everton's first pre-season game of the summer against Swindon Town, and is expected to miss another two weeks.
Toffees boss Roberto Martinez told evertontv: "Mo picked up the injury against Swindon and is recovering really, really well.
"He is a player with a lot of power and a player who I expect to be fit just after the start of the campaign. I think he will miss the opening game but after that he will be close to a return."