The striker is set to return to action for Chile despite being ordered to return to London for the medical team to assess the injury.
Sanchez picked up a hamstring injury while in training with Chile on Tuesday, November 8 and missed their FIFA World Cup qualifiers against Colombia on Friday, November 11.
The striker who has eight goals this season so far for Arsenal was ordered to return to London for the medical team to assess the injury.
The 27-year-old has however defied those orders and returned to training as he hopes to take part in Chile’s qualifier against Uruguay on Tuesday, November 15.
Arsenal boss Arsene Wenger will be keeping a curious eye on Sanchez as he hopes to get his star striker back healthy for this weekend’s Premier League trip to Manchester United
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“I got a text to say that he has a hamstring injury. 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,” Wenger told French TV.
“I believe that with a hamstring injury we have to get access for our medical staff to the 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. We have to preserve the health of Alexis Sanchez.
“He always wants to play and that's where it is a more sensitive case because he's always ready to play even when he's injured.”