The English giants trail Barca by 1-0 from the first tie at Old Trafford last week.
United failed to register a single shot on target in a European game for the first time since 2005.
To make matters worse Barca have not lost a European tie at home for 30 games.
“Barcelona at the Nou Camp is a different prospect”
Ole Gunnar Solskjaer
Now Solskjaer has told the likes of Romelu Lukaku, Marcus Rashford and Anthony Martial to pull their fingers out and do their jobs.
He said: “We know we can turn things round. But Barcelona at the Nou Camp is a different prospect.
“That’s the $100m question. Who can score them (goals).
“That’s why the best strikers are the most expensive ones. We had a couple of decent chances last week, but when you cant work the keeper you cant score.
“We know we will create chances and we have a goal threat, but it’s about taking a deep breath and taking those chances.”
Solskjaer has also launched a withering attack on United flop Alexis Sanchez.
The Chilean has been a huge let down at United since joining them from Arsenal in 2018.
Sanchez was handed a contract worth 500,000-a-week, but has proved to be one of the most expensive failures in the club’s history.
He has lost form and suffered a catalogue of injuries that have seen him in and out of the side.
Old Trafford bosses are desperate to off-load him to the highest bidder this summer.
His wages have caused a split in the United dressing room and Solskjaer admits if Sanchez gets some game time in the Nou Camp he needs to deliver the goods.
Solskjaer added: “Fitness wise he’s available and of course, for Alexis who’s been here and played here, when he’s on the pitch he wants to prove a point for us as well.
“He’s been injured, he’s not had a fantastic season so far and let’s hope he can end the season great.
“We’re in the business end, playing games Manchester United are used to playing in.
“We’re challenging for a semi-final, so let’s hope Alexis, when he’s on the pitch he can be happy with his performance.”