Imanol knows their exit is all but inevitable but believes the Basque side can restore pride at Old Trafford.

"I have to say it could be almost impossible to go through but I believe that my team can compete," the Sociedad head coach said.

"I think we can clean our image, win the game and learn from what happened in Turin.

"We really have to be down to earth and know who we are facing.

"It's the best Man United in the last 10 years. They're battling with Man City for the Premiership. They're really world class physically and quality-wise they're really good.

"We know how difficult it is to cause nerves in Man United even if we score that first goal. But we want to be competitive.

"We're going to try and go out there to win the game but, above all, we need to prove ourselves that we are not that far (from United). We might be far from Man United but we're not as far as the result of the first leg suggests."

Thursday's match will see Adnan Januzaj return to Old Trafford, where Manchester City great David Silva and ex-Arsenal defender Nacho Monreal could also feature.

United will rotate to some extent with the tie all but over and Sunday's Premier League trip to Chelsea looming large, yet Imanol knows it will not be an easy evening.

"I expect the best Man United," he said. "They're a historic team. They'll try and go there and score as many goals as they can.

"Solskjaer himself told me it's the best Man United in years so I expect them to go out there and do the same that we would do in their case.

"We must remember that we are facing one of the best teams in the world at one of their best moments.

"It's a huge difference. Technically we could say we're equal but physically they're really much more powerful.

"Right now, as we speak, we cannot really compete with a club like Man United in terms of squad, etc. It's not just a step, it's a huge leap."