David Moyes is adamant that everyone will be fighting together to try and pull off a great escape and send Manchester United through to the Champions League quarterfinals as he prepares for arguably his biggest game yet as manager. Following a woeful performance in Greece three weeks ago, United trail Olympiakos 2-0 heading to Old Trafford for the second leg of their last-16 tie.

A tumultuous season reached a yet new nadir on Sunday with a 3-0 home defeat to bitter rivals Liverpool to leave the Premier League champions languishing in seventh place. The storm clouds are now concentrating over one of the world’s great clubs and for the first time there is concerted speculation that Moyes’s job is under threat. Still, the former Everton manager is unflinching in his belief that he will be given time to turn things around and is confident of a big performance.

“When you lose in the fashion we did and against one of our biggest rivals there is always a lot of disappointment,” he said of the Liverpool defeat. “We knew it was a big week, but as soon as [the Liverpool match] was over we concentrated on this game. We told the players on Monday morning when we got them back in that the only thing that matters now is this game and our focus is on that.

“Everyone wants to fight for this club. I am not going to tell you we will qualify but I can promise you we will all fight and respect the shirt and make sure all the fans will be really proud of us after that game.”

If United were to fall on Wednesday then it would almost certainly be their last appearance in the Champions League for at least 18 months. Whereas in the past, the prospect of the three-time European Cup winners overturning a two-goal deficit at Old Trafford would have seemed an eminently possible one, there has been little sign this season of the kind of bold, attacking play required. Indeed, not since October have United produced a scoreline at Old Trafford that would send them through on Wednesday, and that was in a League Cup tie with Norwich City.

Moyes will be unable to call upon the creativity of Juan Mata, who remains cup-tied. There are limited options in defense with Chris Smalling and Jonny Evans ruled out, meaning Nemanja Vidic is likely to partner Phil Jones at the back.

Olympiakos arrive in Manchester without their striker from the first leg, Michael Olaitan. But former Barcelona and Real Madrid front man Javier Saviola has returned to training and will compete with Paraguayan Nelson Valdez for a starting berth.

Olympiakos come into the game on the back of clinching their 41st Greek league title and their 16th in the last 18 years with a 2-0 win over Panthrakikos. Before that, though, they had lost back-to-back matches, which were their first defeats of the Super League season. Spanish coach Michel is expecting a tougher test from Manchester United at Old Trafford, but insists his players won’t be intimidated.

“My players aren't scared of anything,” he said, according to UEFA.com. “Maybe the manager is a bit more scared, but they're not. We know the situation at Manchester United but this has nothing to do with us. All we can do is play our game. We cannot rely on their difficulties.

We would like the game to go the same way as it did in the first leg but we know this will be a different Manchester United. There will definitely be more determination and urgency from them. All we want is a good performance. We definitely need one goal. We cannot just sit back and protect our two-goal lead.”

Where to watch: The second leg of the Champions League round-of-16 tie will kick off at 3.45 p.m. ET. Coverage will be provided by Fox Sports 1, with a live stream on Fox Soccer 2Go.