The Red Devils slumped to a 1-0 loss to the Spanish side in the first leg at Old Trafford last week after Luke Shaw scored an own goal.
Manchester United are facing a tough assignment to overturn the deficit given their underwhelming performances over the past few weeks.
The Red Devils have lost their grip on a top-four spot, with Tottenham and Chelsea FC both ahead of Manchester United with five games to go.
Manchester United could only qualify for the Champions League next term by winning the competition this season should the Red Devils miss out on the top four.
However, former Red Devils stat Scholes believes there’s more chance of Manchester United finishing in the top four than beating FC Barcelona.
“Today was the most important one because can you really go to Barcelona and see them winning?” Scholes told BT Sport on Saturday evening.
“It’s doubtful. Of course they’ve got a chance but it’s very difficult. To get in the Champions League, the most realistic chance is the top four.
“Did they prioritise this game? I’m not sure. They’ve got big games coming up but I don’t think this is the best Barcelona team we’ve seen.
“United went to PSG and did a great job there – I think PSG are possibly a better team than Barcelona.”
Manchester United finished in second place in the Premier League table last season in Jose Mourinho’s second campaign in charge at Old Trafford.
Solskjaer replaced Mourinho as the club’s manager in December before the appointment was made permanent last month following some excellent results in the Premier League and the Champions League.
Manchester United lost to FC Barcelona in the Champions League finals in 2009 and 2011.
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