He said: "It is not the changes, it is big players not playing well."
"I wanted to give him his chance because he had shown he was a player who could beat opponents with pace.
"But for me it is not right to talk about only one player, the whole team played badly.
"It is difficult to explain how a team of talented players like ours could give the ball away so much.
"Marseille played well, they pressed us hard and worked well. But we should have been able to create chances behind teams who attack and press like that.
"But we did not create any clear chances. We did have the options, but just failed to take advantage and you do not win if you do not create openings."
He added: "I decided not to change Momo Sissoko. I wanted to substitute Leto to try something different and then I wanted to change the strikers, but had to alter my thinking because Aurelio had picked up an injury and had to come off.
"I was more concerned with doing different things up front, but it was a very bad day for everyone. I prefer not to point the finger at any one player. The whole team played badly."