Mikel Arteta has not ruled out returning to the transfer market as he expects Arsenal to be without Jurrien Timber for the season after the summer signing suffered a knee injury against Nottingham Forest.It was confirmed earlier in the week that Dutch defender Timber will go under the knife after tests showed ligament damage - with Arteta also insisting the number of serious injuries suffered so early into the campaign is a "big worry" for player welfare.

Mikel Arteta has not ruled out returning to the transfer market as he expects Arsenal to be without Jurrien Timber for the season after the summer signing suffered a knee injury against Nottingham Forest.It was confirmed earlier in the week that Dutch defender Timber will go under the knife after tests showed ligament damage - with Arteta also insisting the number of serious injuries suffered so early into the campaign is a "big worry" for player welfare.