Arsenal's captain suffered a left ankle injury after a challenge from Austria's Christoph Baumgartner and was unable to continue playing.
The 25-year-old was clearly struggling and had to be helped from the pitch with the help of two trainers as he winced in pain.
The severity of the issue is not yet known, but it looks very concerning for Arsenal ahead of the north London derby against Tottenham this weekend.
Norway’s national team doctor, Ola Sand, gave an encouraging but still uncertain update to TV2 after the match, saying: ‘Martin is doing quite well now. He got a small ankle sprain. We will see throughout the evening and tomorrow what happens next and what we will do about it.
‘Ankle sprains are difficult to deal with straight away, so we almost have to see how things go forward
‘We will examine him when we are back at the hotel. Maybe we use ultrasound to look at it. If we are unsure, there will be an MRI tomorrow.’
Odegaard was replaced by Kristian Thorstvedt 67 minutes into the game in Oslo which finished 2-1 to the home side after a late Erling Haaland winner.
Arsenal face a nail-biting wait to see how bad the injury is, but Mikel Arteta is already missing a number of players for Sunday’s short trip to Tottenham.
Declan Rice is suspended after a red card against Brighton, summer signing Mikel Merino is out injured, as is Takehiro Tomiyasu.
There are doubts over Riccardo Calafiori and Gabriel Jesus but both could be in contention by Sunday.
Spurs, in contrast, only have Richarlison ruled out, while Dominic Solanke and Micky van de Ven are doubts but hopeful of proving their fitness.
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