Ole Gunnar Solskjaer faces some key decisions at Manchester United this summer

The yellow confetti had barely settled on the Gdansk pitch and Villarreal’s celebrations when the inquest into Manchester United‘s defeat began.

A penalty shootout was all that separated them from glory in the Europa League final but United —and their manager Ole Gunnar Solskjaer — are only too familiar with the fine margins that define success and failure in football.

A fourth season without a trophy means the club are mired in the worst barren spell since Sir Alex Ferguson’s turbulent early years at Old Trafford.

For Solskjaer, what could have been a summer of quiet satisfaction will now involve a significant amount of soul-searching.

The Norwegian and his employers have questions to answer and problems to solve if United are to make the improvements needed to become winners again.

Ole Gunnar Solskjaer has a number of issues to address at Manchester United this summer

FOUR-WARNED

Solskjaer wants up to four new signings to narrow the gap on Manchester City and keep pace with other rivals such as Liverpool and Chelsea who are expected to be stronger in the Premier League again next season.

United are looking for an attacker to play off the right side, and Borussia Dortmund’s Jadon Sancho tops the list of targets for the second summer in a row.

They also want a striker, but signing Sancho would mean there is unlikely to be enough money left to compete for his club-mate Erling Haaland or Tottenham’s Harry Kane — assuming either could be persuaded to move to Old Trafford — having already committed £15million to Edinson Cavani’s salary for another year.

Jadon Sancho of Borussia Dortmund is one of the club’s main transfer targets for right wing

Solskjaer is in the market for a left-sided centre back and United are known to covet Real Madrid’s Raphael Varane and Pau Torres, a key member of the victorious Villarreal side.

A defensive midfielder is also on the list but United are aware that West Ham will demand a huge fee to part with Declan Rice.

The likes of Diogo Dalot, Andreas Pereira, Axel Tuanzebe, Brandon Williams and Donny van de Beek could be sold to generate more transfer funds.

POGBA D-DAY

Issues have surrounded Paul Pogba almost from the moment he returned to Old Trafford from Juventus in a then world record £89m deal in 2016.

The move hasn’t worked out how everyone hoped, and Pogba and his agent Mino Raiola have made no secret of his desire to leave for a second time.

United have resisted until now but next month marks the beginning of a crucial phase in the saga as Pogba will be entering the final year of his contract.

United must decide whether to cash in this summer, try to persuade the Frenchman to sign a new deal, or keep him for the final year knowing that he will leave for nothing at the end of next season.

Paul Pogba’s future has caused uncertainty to hang over the club before and might again 

Having so much uncertainty hanging over such a key figure is in no one’s best interests so it is imperative the issue is resolved this summer.

However, finding a buyer who could give United a sizeable chunk of their money back and meet Pogba’s wage demands narrows the field dramatically.

In theory, United already have a replacement in their squad in Van de Beek. But the Dutchman’s lamentable first season at Old Trafford was summed up by the fact he was not one of the 16 players used by Solskjaer in Wednesday’s final.

DE GEA A STAYER?

David de Gea will go down as the fall-guy in Gdansk for his failure to save or convert from the penalty spot, but United were already facing problems with the Spain goalkeeper.

Having lost his No 1 spot to Dean Henderson, De Gea did enough towards the end of the season to earn a place in the starting line-up on Wednesday after Henderson failed to fully seize his opportunity.

But it’s unthinkable that De Gea could spend next season on the bench when he is the club’s top earner on £375,000 a week.

David de Gea had a night to forget on Wednesday but he cannot be on the bench next term 

United have to move De Gea on or back him and consider letting the ambitious Henderson leave.

They are set to sign Tom Heaton on a free transfer from Aston Villa, primarily as a replacement for third-choice keeper Lee Grant.

But Heaton, until recently a regular in the England squad, could easily be No 2 if De Gea or Henderson go. Either way, it’s a big call.

OLE’S FOLLY

Solskjaer has defied the critics who said he was simply keeping the manager’s seat warm but he knows how quickly things can change.

Defeat by Villarreal has put a different slant on the season. Progress has been made in finishing second to City and reaching the Europa League final, but Solskjaer admitted that another trophyless campaign cannot be considered a success.

More questions will be asked now. Specifically about Wednesday night: could he have been smarter with his tactics and substitutions, including replacing De Gea for the shootout? Unai Emery seemed to make better use of his squad.

Solskjaer needs concrete evidence in the form of trophies next season to fully convince 

More broadly, is he the man to take United forward in the long-term? 

Much of Solskjaer’s tenure has been defined in holistic, cultural terms. But can he have the kind of impact at United as Pep Guardiola, Jurgen Klopp or, more recently, Thomas Tuchel have made on their clubs?

There is no question over Solskjaer’s future, but the doubts will grow unless there is more tangible proof he is moving in the right direction.