Girona, which were in the Champions League last season, were thumped 5-0 on the day.
Afterwards, Michel admits he felt let down by his players and also had doubts about some regarding their commitment to the team.
He snapped: "It's very difficult to digest the feeling of not being a team. The message for the fans is complicated. Everyone has seen that we haven't competed.
"It was very bad. In the end, when you don't compete at 100 percent, a team like Villarreal runs over you. You have the feeling that we played with pride and we haven't done the work we should have.
"We're just starting, but to form a team you have to want it, and the feeling I have is that we didn't want to. Villarreal felt super comfortable. I apologise and ask them to reflect on football. You can't be focused on other things.
"We're not focused on these points. It seems like we're waiting for the transfer window to close to start playing. I'm very disappointed. The whole team has the feeling that we're not a team."
Michel added, "We're in a situation with 6-7 players who could be in or out, and no one is thinking about the responsibility of giving their best in three games before the break.
"That's what hurts me the most because that noise from outside can't influence us, and it is. And the fans are naturally worried. All those doubts that arise outside are caused because we're not focused inside."