The Greek Super League winners are second in Group C, three points behind PSG ahead of their UEFA Champions League clash at Parc des Princes on Wednesday.
An upset win over PSG would assure Olympiacos a place in the knockout stages, and Michel said that should be motivation enough for his team.
"The game against PSG is the most difficult one we have ahead of us because we will be playing against an excellent rival," the Spaniard said.
"But this game is also the most inspiring, because we will be depending on ourselves to qualify for the last 16. If we win, we are through.
"We know that playing against PSG is going to be hard, but we have plenty of hope."
Olympiacos midfielder David Fuster said his side needed to learn from their 4-1 loss to PSG on September 17, when they conceded three second-half goals from set-pieces.
"I think that in the first leg we did not play bad football. We tried our best but we lacked focus and did not take our chances when we had set-pieces," he said.
"It has cost us dear but we will do all what we can to get it right this time.
"It would be a huge achievement to win in Paris. If we win, it means that we would have qualified. It can be the last hurdle.
"We need to stay focussed, we must be hungry and remember where we come from. If we can make it happen tomorrow, it would be ideal."
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