Madrid announced they had signed the Belgium international from Chelsea in June for an initial €100 million ($161M AUD).
Hazard joined up with his new teammates on July 10 in Canada, but was out of shape according to Diego Torres Romano of El Pais.
"Sources in Real Madrid say Hazard arrived seven kilos overweight to pre-season in Montreal. He still hasn't lost half that," Torres tweeted.
"He's a great football, but he doesn't like to train. His passivity in training meant he was overweight the seven seasons he played at Chelsea.
Torres also asserted that someone within Chelsea claimed Hazard was always at least two kilos above his ideal weight.
Real Madrid's pre-season has been somewhat of a disaster; losing their first match to Bayern Munich 3-1, drawing with Arsenal 2-2 and then suffering a humiliating 7-3 loss to local rivals Atletico Madrid.
Hazard played 45 minutes each in the first two matches, and then managed 62 minutes against Atletico.
In those limited minutes, he has failed to score and only once assisted when he set up Nacho with a low cross to make it 6-1 against Atletico.
Torres went on to report that Real Madrid president Florentino Perez was not overly keen on signing Hazard in the past.
"Since 2017, Florentino has halted Hazard's signing for Madrid when it was already half done. Now he is saying within the club that it is a 'Zidane' signing. The president never showed much confidence in the player."
