Simeone concedes they were outplayed on the night in the Champions League.
He said afterwards: "We didn't manage the game well, they were very forceful in all our mistakes and we have to congratulate them. We had been doing a very good job since pre-season and today the game that one doesn't want to happen appeared. We already saw it in the first half and in the second we left the game behind.
"Let's not look for excuses. We didn't play a good game and the coach is responsible. The substitutions didn't make any difference today either. It was a bad game for everyone. Let's get our energy back for Sunday.
"We played badly, we have to accept that. The changes did not give us what we had on other days, and we have to accept that, we were worse, and congratulations.
"There was no lack of attitude or tension, we just played badly and that gives you opportunities to lose. They were forceful and our game was bad."