Rio Ferdinand has said he is concerned that Eden Hazard may have joined a Real Madrid side on the decline.
Angel di Maria scored a pair of goals as PSG took an early lead in Group A of the Champions League.
Hazard joined Madrid this summer in a €100 million (£88m/$112m) move from Chelsea, but his pre-season preparations were cut short by a thigh injury.
"When you go to a new club, especially the size of Real Madrid, you have to earn the right to be the man who gets all the ball," Ferdinand said on BT Sport.
"He's got to do something in the training games, in the actual games that he plays.
"I'm fearful for him that he's gone there at the wrong time.
"This is a team that's ageing, they're not on their way up, they've not got much spark about them at the moment. That is going to affect him and reflect badly on him in the long term."
After winning the Champions League three times in a row, Madrid's run ended last season with a stunning 5-3 aggregate defeat to Ajax in the last 16.
The Blancos struggled badly in La Liga as well last term, finishing in third place and 19 points behind league champions Barcelona.
After watching Hazard's full debut, Peter Crouch also expressed skepticism that the Belgian could be the same player at the Bernabeu that he was at Chelsea.
"Hazard at Chelsea was one of the top five players in the world but watching him tonight he didn't look it," Crouch said.
"At Chelsea he was the main man and everyone was giving him the ball from everywhere. He won't get that at Madrid until he earns it."