The Welsh midfielder limped off the field against Leicester on Tuesday evening and could face a lengthy recovery period.
And Gunners??? boss Wenger said: “It is his third hamstring injury this season. Last year it was a thigh injury but this year it’s a recurrence of hamstrings.
“You cannot say it’s not a worry because after a while the player doesn’t play with the freedom in the mind.
“He’s not overplayed. Before I just played him in every game but since he’s had these problems, I’m a bit more cautious with him.”
The midfielder is undergoing tests from Arsenal’s medical team who are hoping the injury is not as bad as originally feared and that he may be available for their Champions League last-16 first leg tie against Monaco on February 25.
So far this season, Ramsey missed three weeks after injuring a hamstring against Tottenham in September and was out for another five weeks following a recurrence in December.