The Spanish coach saw his side concede a 90th-minute goal from Edinson Cavani to slip to a 2-1 loss at Parc des Princes on Wednesday.
PSG had been reduced to 10 men early in the second half when Marco Verratti was sent off and the visitors equalised on 80 minutes through Kostas Manolas.
With a positive head-to-head record against third-placed Benfica, Olympiacos will progress if both teams win on the final matchday.
Michel was remaining upbeat about his team's chances of reaching the last 16.
"We came close to securing a good result. We are left with a bittersweet feeling – sweet for our effort and bitter for the final result," he said.
"Two minutes before the final whistle, we were virtually qualified for the next round. Now we need to wait until the last minute and remain positive.
"We have to beat Anderlecht. I believe we can do it and go through.
"We have progressed in terms of mentality but we still lack the necessary experience to keep the desired result. We are disappointed with the defeat but remain confident we will qualify."
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