Arsenal head coach Mikel Arteta says he is "concerned" about a muscular injury suffered by Viktor Gyokeres, with the Gunners working to discover the severity of the problem.The Swedish forward missed training on Monday after being substituted with the issue during Saturday's 2-0 win over Burnley.Arteta confirmed he will definitely miss Tuesday night's Champions League match against Slavia Prague but indicated there was uncertainty over just how bad the problem was.

Arsenal head coach Mikel Arteta says he is "concerned" about a muscular injury suffered by Viktor Gyokeres, with the Gunners working to discover the severity of the problem.The Swedish forward missed training on Monday after being substituted with the issue during Saturday's 2-0 win over Burnley.Arteta confirmed he will definitely miss Tuesday night's Champions League match against Slavia Prague but indicated there was uncertainty over just how bad the problem was.