Alexis Sanchez
Alexis Sanchez has scored eight goals for Arsenal this term Getty

Arsenal manager Arsene Wenger has received a double worry after Alexis Sanchez suffered an injury on international duty with Chile while Hector Bellerin has reportedly failed to complete a training session with Spain's under-21 team on Tuesday (8 November).

The severity of their problems is still uncertain but the news is of paramount concern for the French boss as, just after the international break, the Gunners have a crucial trip to Manchester United on 19 November.

Chilean publication La Tercera reported, on Tuesday morning, that Alexis had "set the alarms bells ringing" in his national team after the Arsenal star withdrew from Tuesday's training session due to a muscle injury. Alexis allegedly started the session with the rest of his teammates but was forced off after suffering a knock in the femoral triceps.

The Arsenal star was consequently sent for medical tests and the Chilean football federation have now confirmed the worst through an official statement.

"The Chile medical department informs that Alexis Sanchez suffers a low grade muscular injury," the national federation said. "He will remain in Santiago (Chile) under treatment and in evaluation for the meeting between Chile and Uruguay."

This means that Alexis has been ruled out for the Chile trip Colombia on Thursday night (10 November) but he may still be ready to return to action for his national team in the World Cup qualifier with Uruguay at home on 15 November.

That Alexis has not completely withdrawn from the national team should give Wenger some hope ahead of having his star fit for the forthcoming trip to Manchester United on 19 November.

Meanwhile, the French boss has received a second concern ahead of the trip to Old Trafford from the Spanish under-21 camp, after Bellerin also reportedly failed to complete the training session with the rest of his teammates.

The Arsenal right-back played the full 90 minutes during the 1-1 draw against Tottenham but last week was left out of the Champions League trip to Ludogorets after Wenger revealed the Spaniard "had a little incident in the last minute of training."

AS claims the Arsenal right-back joined the Spanish under-21 team with some niggles and so couldn't complete the Tuesday training session with the rest of his teammates, working instead on his own alongside Athletic Club Bilbao forward Iñaki Williams.

The Spanish publication thus claims that both Spanish under-21 internationals are in "doubt" for Friday's 2017 euro qualifier against Austria.

However, the Spanish football federation are yet to make any official update on the Arsenal defender.