MANCHESTER UNITED manager David Moyes accepts his team have a big job on their hands as they seek to book a place in the Champions League last 16 tonight.
The task is straightforward – victory over Bayer Leverkusen will be enough to confirm United's place in the knockout phase with a game to spare.
But achieving the aim will be rather more difficult, as Sami Hyypia's men have been in outstanding form this season.
They are currently second in the Bundesliga and the only time they have failed to win at the BayArena was their draw with European champions Bayern Munich last month.
Under the circumstances, it is little wonder Moyes believes the fixture represents the toughest United will face in their group campaign.
"We have a big job to do," he said. "Bayer Leverkusen have been in great form at home.
"My first feeling when I saw the group was that Shakhtar Donetsk away would be a real tough game. It did prove to be that way and we ended up with a draw there.
"But Leverkusen are in good shape in the group themselves. We know we are going to have a game on our hands."
United's problem stems from the fact they failed to overcome Real Sociedad three weeks ago.
That goalless draw in Spain represents the Basque outfit's only point in the entire competition.
So, should United fall to their first defeat in the competition tonight and Shakhtar win, it will set up a winner-takes-all confrontation with the Ukrainian champions at Old Trafford in a fortnight.
It is not entirely a palatable prospect considering the uncertain form the Red Devils have been in.
That is why Moyes could even nurse a sense of relief on the flight back to Manchester if his side manage even a share of the spoils.
"We had a great opportunity in Sociedad to pull away further, but we didn't take it," the Scot said.
"We want to try and get the work done as soon as we possibly can, but if it has to go to the last game so be it."
Nevertheless, it is a pity Moyes should find his squad so stretched.
The former Everton boss was already aware he would be without Marouane Fellaini following the midfielder's red card in San Sebastian.
Michael Carrick's Achilles injury has robbed him of another senior player from his midfield ranks.
However, prior to the afternoon departure, he also had to strike a pen through the names of Nemanja Vidic and Robin van Persie.
Both men missed Sunday's draw at Cardiff and Van Persie has not recovered from the combination of toe and groin complaints that have been plaguing him for a couple of months.
Vidic was able to train in the morning. Evidently though, the Serbian is not fully over the concussion he suffered against Arsenal immediately prior to the international break.
"They are both injured," Moyes said. "Nemanja Vidic had concussion and Robin has a problem with his groin. Neither of them are long term, but they are not quite ready yet."
That could mean they will be fit to face either Tottenham or Everton in the Premier League fixtures that follow the German trip.
Against Leverkusen, though, it could herald the immediate return of Phil Jones to central midfield after the groin injury he picked up on England duty a fortnight ago.
"Jones has travelled and is in the squad," Moyes said.
"It is normal to lose players to injury and suspension at big clubs.
"But we have a squad which we will be able to use and they can show what they can do."
For their part, Leverkusen are confident going into tonight's match, with striker Stefan Kiessling convinced they can beat United.
The German outfit left Old Trafford with regrets in September, when they lost 4-2 to David Moyes' men.
But on home soil they have been particularly impressive, failing to win only against Bayern Munich, who escaped with a draw.
So, with United's faltering start continuing at Cardiff on Sunday, Kiessling is looking ahead with optimism.
"The first time we played them, we showed Manchester United too much respect and were very anxious," said Kiessling, who has scored 12 goals in all competitions this term.
"Since then we have played a lot of good games and achieved some excellent results.
"At home we are a real force and, don't forget, this is not only an important game for us, it is for them as well."