Michel admitted that Girona are no longer the same team that took LaLiga by storm last season and urged them to rediscover their identity.
Girona were the surprise package last season, going toe-to-toe with Real Madrid and Barcelona in the title race before eventually finishing third in LaLiga.
However, the club let go of Golden Boot winner Artem Dovbyk, who scored 24 LaLiga goals last season, and influential midfielder Aleix Garcia in the transfer window.
Though they brought in reinforcements, including Donny van de Beek from Manchester United, they have not yet found their rhythm, losing each of their last three games in all competitions.
In that run, which includes a 1-0 defeat to Paris Saint-Germain in their Champions League debut, they have managed a combined eight shots on target from 20 attempts, and netted just one goal, failing to score in each of the last two.
"Things happen for a reason," Michel told a news conference. "Our reality is that we have lost three games in a row, and it is difficult because people expect the team to win.
"Right now we are not the team we were last year, we are another one."
"With the ball, we are not hurting the opponent and this means that we have to suffer. We must play with fewer touches and be able to look up and for that I need high intensity. This is a machine that has to work now.
"Right now we are 12th and that is our reality. We have to improve to win games continuously as people expect. We have to go through the process, and we will suffer."
Winger Portu is available after an ankle knock, giving Michel a fully fit squad as he prepares to face the club where he spent most of his playing career and took his first steps into management.
"It's a special match which I never enjoy. It will always be like this," Michel added. "[Rayo] is the club where I have lived, and my life is in Vallecas.
"They are a great team in every way. They are the team that presses the most and best in the league, and they have a higher intensity than anyone else. It isn't easy to create scoring chances against them."