Diego Simeone's men might have reached the final last season, but they were dealt a rude European awakening as they fell to a surprise defeat at the Karaiskakis Stadium.
The Red Devils must overturn a two-goal deficit to see off the Greek champions, advance to the last eight of the competition and ease the pressure on their manager.The Premier League holders welcome the Greek club - who secured their fourth straight league title on Saturday - for the second leg of their last-16 tie, desperate to overturn a 2-0 deficit.
The Portuguese forward has no desire to leave the Spanish capital any time soon following Champions League and European Championship glory in 2016.
"So happy" after scoring in the 2-0 win over Manchester United FC, Alejandro Domínguez wants another Olympiacos FC coup at Old Trafford: "We are here to change history."
The hard-running Argentinian midfielder could not hide his emotions after the triumph in Piraeus, telling UEFA.com: "I am so happy. I am very satisfied with the team's work and the victory we achieved. I believe we have made a big step – a giant leap forward. The tie is not over, we have the away leg to come, but we should enjoy today's result. For me, this is a historic night for the club and we are thrilled."