Martin Odegaard limped off with an apparent ankle injury in Norway’s 2-1 win over Austria on Monday night in what could be a major blow to Arsenal ahead of the north London derby.

The Gunners midfielder had started the game against Austria in Ullevaal, but was forced off in the 67th minute. The incident occurred following a challenge from Christoph Baumgartner which saw his foot stick in the turf causing a nasty looking injury.

“Martin Odegaard’s injury looked bad in the dressing room as well I saw he was sitting with the physiotherapists around him but he had no chance to continue and we know it was an ankle sprain,” Norway coach Stale Solbakken told broadcaster TV 2. “Yes it’s a sprain, and as those of us who had played football know, with luck it can turn out ok if the ligaments aren’t torn.”

He did try to walk off to be substituted by himself but needed the help of medical staff. Unfortunately for Odegaard, his club, and country, Norway Doctober Ola Sand couldn’t give an immediate timeframe for his return.

“He got a small ankle sprain,” said Sand. “We will see, maybe we use ultrasound to look at it. If we are unsure, there will be an MRI tomorrow.”

The Gunners first go to London rival Tottenham Hotspur on Sunday then open their Champions League program at Atalanta, the Europa League winner, four days later in Italy.

It will be a huge test for Arsenal, who will no doubt need their key players available as they battle across two fronts at home and in Europe.