A Robin van Persie hat-trick saw the hosts record an emphatic turnaround in the tie, but the Greek champions' coach believes his side should have scored at Old Trafford
Olympiakos arrived at Old Trafford with a two-goal lead from the first leg but were sunk by a Robin Van Persie hat-trick as United roared back to win 3-0 and book their place in the quarter-finals.
But Michel believes it could have been a different story had his side converted their opportunities, with David De Gea forced into a handful of fine saves for the home side.
"We had our chances but failed to convert them," he told Uefa.com.
"And teams who do not make the most of their scoring opportunities at this level, end up paying for it.
"I would like to congratulate my players on their effort. Looking at the result, one might think that it was a one-way match – but that was not the case.
"Football is played in both areas and today we committed errors at both ends."