The 27-year-old Frenchman has scored just five goals in his last 14 games for the Gunners in all competitions.
Despite Giroud's waning form in front of goal, Wenger believes that the forward is still an important part of the team.
"He has a fantastic spirit, Olivier Giroud is a fantastic team player," Wenger told the club's official website. "He has gone through a little bit more of a difficult period, but that happens to any striker.
"Striker is the most demanding position. He has played many, many games - more games than any other striker in the Premier League, and that of course is very demanding."
Arsenal are back in Premier League action on Tuesday against West Ham United at the Emirates Stadium.