Mikel Arteta has revealed Arsenal are 'actively looking' in the transfer market after Gabriel Jesus suffered a serious knee injury. 

The Brazilian was forced off on a stretcher following a collision with Bruno Fernandes towards the end of the first half of the Gunners' FA Cup third round exit. 

Jesus is set to undergo further tests on Tuesday to determine the severity of the injury but there are already fears that he has suffered cartilage or ligament damage to his knee 

He will likely miss the remainder of the season in another injury blow to Arteta, who is already without talisman Bukayo Saka. 

'We are actively looking in the market to improve the squad. That's been like that since day one,' the Arsenal boss said ahead of Wednesday's north London derby.

'It would be naive not to do that. It's an opportunity to improve the squad. We are looking. We are trying. Let's see what we can do.' 

The injury to Jesus leaves Arsenal with just one fit striker, with Kai Havertz set to continue to play a lead role in the side. 

The German forward squandered some gilt-edged chances in the loss to Manchester United to continue Arsenal's recent struggles in front of goal. 

Arteta also admitted he is 'worried' about the significance of the injury to Jesus. 

'We know more now and it is not looking good at all. But we need to review one more specialist. So we will have more information this afternoon,' the Gunners boss added. 

'I don't want to confirm anything until we have the final report this afternoon. We are very worried today.'