Wenger: Eden Hazard's poor form is because he is 'too heavy' at Real Madrid
He became Los Blancos flagship signing since the loss of talismanic superstar Cristiano Ronaldo to Juventus a year before.
Zinedine Zidane, who returned to the Madrid hot-seat last season, oversaw Hazard's integration into the squad.
However, after ten games for the Spanish giants, the Belgian has only managed one goal so far this season.
On Wednesday, Real Madrid romped to a 6-0 victory over Galatasaray in the Champions League.
But it was the 18-year-old Rodrygo, not Hazard, who took the headlines by scoring a hat-trick.
Arsene Wenger was a pundit for the game and he believes Hazard is being weighed down by his own body, rather than expectation.
"He is not the type of guy to be [over-awed at Madrid] but I don't know him well enough to assess that," Wenger told beIN Sports (as reported by Goal).
"I think it was more down to physical reasons. He became too heavy and what you read in the papers.
"If you want to make a horse lose a race, you put two kilos on a horse of 500kgs and it's enough."
In Hazard's last season at Chelsea, he contributed an impressive 16 goals and 15 assists.
Wenger thinks that kind of form will only return with improved fitness.
"I feel we have not seen the Hazard we know in England yet," Wenger said.
"He was not physically fit after he was injured. He is not a player who is usually impressed by anything.
"But he looks to me that he doesn't have the same confidence he had at Chelsea."
Real Madrid are up against Eibar next in La Liga, where Hazard will be keen to reboot his season before the international break.