The two sides meet in the first leg of the tie tonight in Greece. Olympiacos are currently riding high at the top of the Greek Super League, while United have been buoyed by news of Wayne Rooney's contract extension and a 2-0 victory at Crystal Palace at the weekend.
Ahead of the clash Issa, who has himself experienced playing against United for Marseille during the 1999/2000 season, told us that excitement for the match is high in Greece and he hopes his side can deliver.
"Everyone is looking forward to it. It's a great honour to play against a big club like United. They are one of the best teams in Europe," he said. "We have been trying to play some attractive football this season with some young players in our team, so it should be an interesting game and a great match for us and our fans."
When asked how Olympiacos will go about curbing the threat of Wayne Rooney and Robin van Persie, Issa added: "We have been working on that for a while. We know we have to be at our top level. It will be a challenge for our defenders, but everyone in the team will need to work hard to stop players like that. We will do the best we can."