By Editor Wayne Veysey | Former Evening Standard, Press Association and Goal chief correspondent with 17 years experience of breaking big stories, including exclusives like this

Follow me on Twitter @footyinsider247

Alexis Sanchez has been given permission by Arsenal to fly back to Chile undergo the first phase of his rehabilitation, Football Insider sources understands.

Sanchez will be absent for around three weeks with the hamstring injury he sustained against Norwich last weekend.

An Arsenal source has told Football Insider that the forward will be allowed to return home for a short break and spend some time doing his rehab with the doctors from the Chile national team.

Sanchez is set to miss Premier League clashes against Sunderland and Aston Villa, as well as next Wednesday’s must-win Champions League match at Olympiakos.

But the scan of his injured right hamstring showed on Wednesday that it is not as bad as initially feared – when there was the prospect of a six-week absence – and he is targeting the showdown against Manchester City on 21 December for his comeback.

The Gunners are confident their leading scorer with nine goals this season will be firing for the heavy festive schedule.

Sanchez limped off with what Arsene Wenger confirmed was a hamstring problem in the second half of the Gunners’ 1-1 draw at Norwich on Sunday, prompting fears of a lengthy lay-off of four to six weeks.

But the assessment of the club’s medical team is that the injury appears not to be a really serious one.

Sanchez grabbed the back of his his right leg 60 minutes into the Carrow Road clash after chasing a goal-scoring opportunity. He began to limp and then called for medical attention. He was immediately substituted and replaced by Joel Campbell as he was escorted off the pitch by physio Colin Lewin.

Home comforts: Sanchez will return to Chile to undergo the first phase of his rehab

Home comforts: Sanchez will return to Chile to undergo the first phase of his rehab

Asked by Sky Sports on Sunday night if the amount of football Sanchez has played contributed to his injury, Wenger replied, “You could say that. At the moment on the striker front we have not much choice because [Danny] Welbeck is out, [Theo] Walcott is out, [Alex] Oxlade-Chamberlain is just coming back.

“Just because you repeat the games doesn’t mean you get injured, maybe the travelling to South America as well. I would have rested him today but he felt perfectly alright before the game and he declared that he had no problem.”

Of Arsenal’s 19 Premier League and Champions League matches this season, Sanchez has started 18 and been a second-half substitute in the other one, on the back of an exhausting programme over the last 18 months.