You-know-who was the star with the first two goals, one of which was aided by a disastrous defensive clanger.
Find out how all the players rated here:
De Gea 4. Made a howler for Messi’s second goal. Partially made amends with a fine stop from Roberto but it was too late.
Lindelof 5. Had his hands full with Alba and Coutinho and couldn’t always contain them. Rarely got forward.
Smalling 7. Defended with pace and anticipation to contain Suarez and prevent further damage. Probably United’s best player.
Jones 5. Made some solid defensive interventions but was regularly tormented by Messi, including the second goal.
Young 4. Should have done more to stop Messi’s opener and his night didn’t get any better, looking past his sell-by date.
McTominay 7. Squandered a great early chance by miscontrolling, but otherwise a solid display with some robust challenges.
Fred 6. Put himself about in the centre of the field and kept things tidy, but was beaten by Messi for both goals.
Pogba 5. Good early pass to release Rashford and tried his luck with a couple of hopeful long-range shots but offered little else.
Rashford 6. Hit the bar after 35 seconds and scuffed another shot. Always a threat with his pace but lacked end product.
Lingard 5. Playing in the middle, he posed little danger except a long-range shot narrowly over the top just before being replaced.
Martial 5. Showed plenty of pace down the left early on but soon faded and was replaced by Dalot just after the hour.
Dalot 6. Came on for Martial and tried to get forward down the right, nearly creating a goal for Sanchez.
Lukaku 5. Added a more physical presence to the forward line towards the end but had little impact with the game gone.
Sanchez 6. Received a warm reception from fans of his old club and drew a fine save from Ter Stegen with a header.
Solskjaer claimed a special place in the hearts of United supporters 20 years ago when his last-gasp strike against Bayern Munich at the Camp Nou sealed an unforgettable treble.
Now the club’s manager, the Norwegian returned to the ground on Monday as his side bid to overturn a 1-0 deficit in the return leg of their Champions League quarter-final in Barcelona.
Yet Solskjaer refused to dwell too much on the past and is fully focused on the task at hand, urging his side to believe they can prevail against the Spanish champions on Tuesday night.
He said: “Of course it’s a fantastic memory for me. It’s the only time I’ve been on the pitch, but I don’t really look back on that night too often.
“My job now is to make us play better than in the first game.
“I was a player back then. In football anything can happen at any time and we know that we can still be in this tie.
“It’s about the quality though. We need to defend well but going forward we need to score. If we keep a clean sheet, we can still be in the tie in the 93rd minute.”
Solskjaer thinks his players should be emboldened by their fightback against Paris Saint-Germain in the last 16.
Following a 2-0 loss at Old Trafford, United responded in spectacular fashion with a 3-1 victory at the Parc des Princes to progress on away goals last month.
Solskjaer recognises the abilities of a Barcelona side who have won four European Cups since 2006 but remains in a bullish mood.
He said: “That memory from PSG will help the players, will help us as a team. We know we can turn things round.
“Of course Barcelona here at the Camp Nou is a difficult prospect but the memory from that night will live with the players.
“It’s not that long ago and we’re one goal better off.”
Alexis Sanchez was among United’s 22-man travelling contingent and is in contention to make a return against his former club after six weeks on the sidelines because of a knee injury.
The Chilean, who scored 47 times in 141 appearances during three seasons with Barca between 2011 and 2014, has endured a largely miserable time at United as a haul of five goals in 41 games would suggest.
Solskjaer said: “For Alexis it’s a big night and when he’s on the pitch I’m sure he wants to prove a point.
“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 for us.
“We are in the business end of the season, we’re playing games that Man United are used to playing.
“Let’s hope Alexis can be happy with his performance when he is on the pitch.”
Solskjaer reaffirmed his belief that Paul Pogba will remain at United beyond the end of the season after the Spanish media questioned speculation linking the Frenchman with a summer move to Real Madrid.
Solskjaer added: “Paul’s focus is on Man United and performing here.
“He has been fantastic since I’ve come here and I’ve no doubt that he will perform for Man United as he has done lately.
“I don’t think they (the fans) should worry too much.”
Alexis Sanchez was among Manchester United‘s travelling contingent as they bid to overturn a 1-0 deficit in the return leg of their Champions League quarter-final against Barcelona.
The Chilean has been sidelined for the last six weeks because of a knee injury but could return to bolster an attack that failed to register a shot on target in last week’s defeat at Old Trafford.
Midfielder Nemanja Matic and full-back Matteo Darmian were also part of the 22-man squad heading out to Barcelona on Monday morning but Ander Herrera and Eric Bailly miss out.
But it is the inclusion of Sanchez, who scored 47 times in 141 appearances during three seasons with Barca between 2011 and 2014, that could prove a talking point at Ole Gunnar Solskjaer’s press conference later on Monday.
The 30-year-old has struggled to hit top form since signing for United in January 2018 and, even though several injuries have hampered his progress, a haul of five goals in 41 appearances represents a miserable return.
Luke Shaw has travelled with his team-mates despite the full-back being suspended for the Nou Camp clash after being cautioned against the LaLiga champions last week.
United will be aiming to come from behind for the second time in a row in Europe’s elite club competition, having seen off Paris St Germain in the last 16 despite trailing by two goals after the first leg.
Marcus Rashford’s last-gasp penalty sealed a memorable 3-1 victory at the Parc des Princes last month, although the United striker is wary of putting too much emphasis on that result.
He said: “We’ll always take confidence from that but we also understand that it’s not PSG, it’s a different match, a different atmosphere, it’s a completely different ball game.
“We go there confident but if we’re going to win it’s probably going to be different to how we did it in Paris.
“For us now we need to forget about the past. We know we’ve done it before, but all the focus has to be on how we’re going to do it again because they’re a strong team.”
Provided by Press Association Sport