Montreal Impact coach Thierry Henry has praised the work of Mikel Arteta at Arsenal.
But Henry says he needs to clear up the Mesut Ozil "case".
Assessing Arsenal's recent managerial appointments, Henry told CBS Sports: "So now it was Unai Emery and now Mikel Arteta.
"It's not easy to go after Arsene Wenger. It's not easy at all. With Mikel, I see that the passion is back, a certain happiness is back, he gives them a good solidity.
"Now he needs to deal with Ozil case and other cases, but that doesn't happen overnight.
"When you're in a team with someone, you need to make sure you can clear some stuff, because it just doesn't happen overnight.
"So he needs to bring in players he needs to fit his system and that takes time. And on top of that, this league takes even more time because the competition is crazy."
