By London correspondent Tony Hughes

Arsenal are set to be without key duo Alexis Sanchez and Hector Bellerin for their showdown against Manchester United after the international break.

Arsene Wenger confirmed on Thursday that Sanchez has suffered a hamstring on international duty, although he is still awaiting an exact diagnosis on the injury.

It also emerged on Thursday night that Hector Bellerin could be sidelined for a month with ankle ligament damage.

The massive double blow will radically alter Wenger’s plans for the clash at Old Trafford, which is a Saturday lunchtime kick-off.

Olivier Giroud is expected to return to the starting line-up in Sanchez’s absence, while fit-again Carl Jenkinson is the most likely replacement for Bellerin.

The Gunners are unbeaten in 16 games in all competitions but their excellent run will now come under threat, with the United clash followed by a Champions League home match against Paris Saint-Germain.

Wenger is expected to name his strongest available XI to face United, which is mean nine of the starters in the 1-1 draw against Tottenham keeping their places.

Jenkinson could slot into a defensive unit,featuring Petr Cech, Nacho Monreal, Laurent Koscielny and Shkodran Mustafi.

Ball-winning midfielder Francis Coquelin will is once against likely to be paired by Granit Xhaka if Santi Cazorla is once against deemed not fit enough to start.

Aaron Ramsey’s recent return to action may give Wenger a headache but the Wales international is more likely to be a contender to start in a more advanced role that makes use of his considerable goal threat.

Despite a lack of productivity against Tottenham, Arsenal’s attacking midfield trio of Alex Iwobi, Mesut Ozil and Theo Walcott is expected to remain intact.

Victory for Arsenal at Old Trafford could see them extend their lead over United to nine points. If United win, on the other hand, they could come within just three points of the top-four.

In other Arsenal team news, here is how Gunners fans have reacted on Twitter to losing Sanchez to injury.