Obertan, who knows him from time shared at the Clairefontaine Academy, has assured supporters he is a "cool guy" - with magic in his boots.
He told the Sunday Sun: "I have always known about Hatem as a footballer.
"I think everyone in France knows Hatem because he is one of the most talented French footballers.
"We used to play against each other in France and we both went to Clairefontaine, the Academy, together too.
"I knew a lot about him - not the person, the player. I knew of his quality and it has not surprised me to see what he can do.
"As a person I think he has grown up because of his injury.
"When you have serious injuries like he has had, you think about football and life in general too."