Marseille No2 Passi: QPR's Barton set for Euro debut
Although he is not yet up to match fitness, Passi has been encouraged by the way Barton has tried to integrate himself into the team.
"He's spent two months without training normally. Physically, he'll need a little more time but it's possible that he takes part in the Europa League match," Passi said.
He added: "He's a technically very sound player, he participates a lot and he's trying to integrate himself to the very full in our football culture."