Montpellier head coach Rene Girard fears an in-form Olivier Giroud could return to haunt his former side on Wednesday.
The Arsenal striker will come face-to-face with his former club at the Emirates in the sides' Group B clash on Wednesday.
Giroud has scored four goals in four games for the Gunners but Girard issued a warning to the striker and said Montpellier were well aware of how to stop him.
"Look, we know Olivier (Giroud) very well, he is a very good striker," Girard said.
"Unfortunately for us, I think he just made a great come back and is scoring goals, he is now at his best level, but we have the defenders who can stop him.
"I think for him the first game was very emotional, it was complicated to come back to Montpellier.
"But here he would like to show us he is not here by mistake. But we already know it because he is a great guy who we all like."
Montpellier have no chance of qualifying and are five points adrift of third place in the group and a Europa League berth, yet Girard insisted it is still an important match.
"It's an important game for us. It's a great game for us, a very crucial game," Girard said.
"As I said to the boys, the Champions League is over, but we still have a little hope with the Europa League.
"But the most important thing is to prepare for the following Ligue 1 fixtures.
"It will be hard so we need to fight back in the table. We'll play against Bordeaux, Lille, Lyon - many complicated games.
"We've made a good start against Paris and Valenciennes so against Arsenal we need to keep playing like that."