Arsenal defender Laurent Koscielny says his team mate and compatriot Olivier Giroud is suffering from fatigue.
Giroud has been in fine form for the Gunners so far this season, scoring 10 times and assisting five in all competitions.
However, a lack of alternative options up front means the French international has played 24 times for club and country this season - more than any other outfield Arsenal player.
Giroud cut the shape of an exhausted figure during the 1-0 defeat to Manchester United on Sunday and Koscielny admits his team mate for club and country may be suffering from fatigue.
The French defender told The Sun: "It's true that he's not scoring but he is setting them up, like he did against Dortmund.
"But he's also playing game after game and hasn't had a rest, so maybe he's feeling a bit of fatigue.
If Giroud was to get injured Arsene Wenger would have no option but to start want-away striker Nicklas Bendtner up top - something fans fear.
The Dane reiterated his desire to leave Arsenal last week and it is widely considered that fans feel the same way.
Bendtner offered little when coming on for Santi Cazorla at Old Trafford and Koscielny admits Giroud is crucial to Arsenal's chances this season.
"He's very important for us," he continued. "He is strong and always answers the call on the pitch.
"If you look at the games, he weighs enormously on the opposition's defence. All the balls he wins are in the air with his back to goal. He works very hard up front."
Koscielny has also backed his Arsenal team mates to recover from their disappointing defeat to the Premier League champions, saying the team have learnt valuable lessons.
He added: "We are still confident. The lessons to learn are that we were too shy in the first half and we weren't able to play our game.
"The second half was better, even if Manchester United let us have the ball.
"But we'd played a lot of games so maybe we dropped off a bit physically. Now we have 10 days off and we will have to get the fire going again at home to Southampton."