Aston Villa defender Philippe Senderos has picked up an injury on international duty with Switzerland.
The 29-year-old picked up the problem during Switzerland's 1-0 defeat to Slovenia in Euro 2016 qualifying.
Senderos is now expected to miss Villa's trip to Everton this weekend.
"Philippe has a thigh muscle strain. We'll have to see how it reacts," Swiss team doctor Cuno Wetzel said.
"Normally a player is out of action for some time with a muscle injury of this type."
