By Arsenal correspondent Tony Hughes

Arsenal are sweating on the fitness of Alexis Sanchez after he limped off in Sunday’s Premier League clash against Norwich.

The Chilean pulled up with what appeared to be a hamstring injury as he chased a goal scoring opportunity in the second half.

Sanchez grabbed the back of his his right leg, began to limp and called for medical attention. With 60 minutes of the match gone, he was immediately substituted and replaced by Joel Campbell as he was escorted off the pitch by physio Colin Lewin.

It is the latest in a series of soft tissue injuries suffered by Arsenal this season. Aaron Ramsey and Alex Oxlade-Chamberlain have only just returned to the team after suffering hamstring injuries that kept them out for six and five matches respectively.

Sanchez could be absent for at least three weeks in what would be a major blow to Arsenal’s Premier League title hopes.

Arsenal drew 1-1 at Carrow Road after Mesut Ozil’s superbly-taken opener was cancelled out by Lewis Grabban’s equaliser.

Sanchez was the second Arsenal player to be forced off through injury after Laurent Koscielny suffered a hip injury early in the match and was replaced by Gabriel after 11 minutes.