Chile face Colombia on Thursday night without Sanchez after he suffered the injury having met up with the squad following Arsenal's 1-1 draw against Tottenham last weekend.
mercurial superfly cr7 blue But the Copa America holders will keep the 27-year-old in their ranks in the hope he can be passed fit to face Uruguay on Tuesday.
Wenger, who has been utilising Sanchez as a central striker for much of the season, has seen the former Barcelona man hit eight goals in 15 games for the Gunners and wants to know he is safe to play in the second international game rather than risk losing him over the busy festive schedule.
"I got a text last night to say that he has a hamstring injury," he told beIN Sports.
mercurial vapor v red Profiles Alexis Sanchez
"We have to get access for our medical staff to the MRI scan to see what grade it is, how bad it is and make absolutely sure they don't make any suicidal decision that could harm his future for two or three months.
elastico superfly black "That is absolutely important. It's a grey area between the national team and the club team and of course they look at their own results which I can understand, but we have to preserve the health of Alexis Sanchez."
16+ PureChaos white Sanchez missed almost two months of last season after suffering a hamstring injury at Norwich last November and Wenger knows the player will always look to play through the pain barrier.
"The team from Chile has travelled without him and they kept him to try and get him fit to play Uruguay for the second game on Tuesday night," he added.
superfly v red "He always wants to play and that's where it is a more sensitive case because he's always ready to play even when injured."