Arsenal full-back Hector Bellerin is set to be out of action for the rest of the month after damaging an ankle ligament during the North London derby against Tottenham Hotspur, IBTimes UK sources understand. Medical tests confirmed the worst for manager Arsene Wenger ahead a crucial run of fixtures that will see the Gunners visit Manchester United on 19 November four days before a Champions League clash with Paris Saint-Germain.

The 21-year-old right-back has been carrying an ankle issue for weeks after picking up a knock in the previous international break, during Spain Under-21s Euro 2017 qualifier against San Marino U21s on 5 October.

The Spaniard looked to have shaken off that niggle, but last week was forced to miss Arsenal's trip to Ludogorets Razgrad after Wenger revealed he had gone down with a "little incident in the last minute of training". Bellerin recovered in time to play the full 90 minutes during that 1-1 draw with Tottenham.

However, IBTimes UK understands that the Spaniard suffered a further knock during the derby stalemate, aggravating the problem. The right-back originally thought it was only a minor issue and subsequently travelled to Spain to join the U21 squad ahead of that double European Championship playoff qualifier with Austria.

However, after been unable to train with his teammates, Bellerin was forced to withdraw from his national team on Wednesday evening with fears that he could have damaged his ligaments. Subsequent medical tests have confirmed the worst fears for Arsenal and he should be out of action for between three and four weeks.

Bellerin will miss the remainder of November, including the crucial trip to United upon the resumption of the Premier League campaign, as well as the visit of PSG in Europe.

Arsenal face four games in the space of 11 days before the end of the month. Following the games with United and the Ligue 1 champions, the Emirates Stadium outfit will host Bournemouth in the Premier League (on 27 November) before their EFL Cup encounter with Southampton on (30 November).

Bellerin's ankle injury is similar to the one sustained by his compatriot Lucas Perez in the EFL Cup clash with Reading last month. While the forward was ruled out for between six and eight weeks, Arsenal doctors are more optimistic about Bellerin.

The news is nevertheless a new massive blow for Arsenal and comes during an international week when the Chile football federation revealed that Alexis Sanchez has suffered a low-grade muscular injury during a training session.