The Wales international limped off after coming as a substitute during the Gunners’ 2-1 midweek Premier League victory over Leicester City. The midfielder is set to be out of action for the next few weeks.
Sanchez was also replaced in the second half and the Chilean could miss the north London club’s FA Cup fifth round clash against Middlesbrough at the Emirates.
“Aaron Ramsey will be out, he has a little hamstring strain. Alexis is still not able to go out, he could be short again for Sunday,” Wenger told Arsenal’s official website.
“We haven’t found the underlying reason. There is an underlying reason that is certainly medical or bio-mechanical because he [Ramsey] is a guy who is serious, works hard, has a controlled and disciplined life, so there’s no obvious reason why he should have muscular problems.”
Meanwhile, Jack Wilshere has returned to training after spending the last few months on the sidelines with injury. However, Wenger admitted the England international is still lacking match fitness to make a comeback.
“Jack Wilshere’s back in normal training but has been out for [more than two] months and misses competition. He worked very hard and is focused, committed, but it will take him a while to get back to competitive level,” Arsenal manager said.
“He’s motivated and focused to come back as quickly as possible. He worked very hard but he has still been out for [more than two] months and what he needs now is to get back.
“Competition gives you that sharpness that training cannot give you because it’s about a combination of fitness and decision-making – and speed of decision-making. It takes a while to get that back.”
Sanchez and Ramsey now join Mikel Arteta, Mathieu Debuchy and Alex Oxlade-Chamberlain, who will also miss Sunday’s FA Cup clash at the Emirates.