Sanchez was involved in Chile's 3-0 defeat to Brazil on Tuesday night, with the Gunners player unable to help his national team to the World Cup despite playing the full 90 minutes.
Wenger has acknowledged that the 28-year-old was involved in a "physical" game and admitted that the attacker is not guaranteed to start at Vicarage Road.
The Frenchman told reporters: "I will have to speak to him. Yesterday, I watched the whole game and I must say he got some special treatment.
"It was very physical and mentally I will have to assess the situation."
Sanchez has scored just one goal in seven appearances in all competitions this season.