Manchester United's recent poor results have left Ole Gunnar Solskjaer realising he has a serious job on his hands if he wants to turn things around at Old Trafford.

All seemed rosy during Solskjaer's period as interim manager as he inspired a remarkable upturn in form, got key players back on side and guided United into the Champions League quarter-finals against the odds.

But since Solskjaer took the wheel permanently in March, United have lost four of six games across all competitions, including a humiliating 4-0 defeat at the hands of Everton on Sunday.

Before that game – and following the 4-0 aggregate loss to Barcelona in the Champions League – Solskjaer questioned the attitudes of his players, saying some needed "a reality check".

With bitter local rivals Manchester City visiting on Wednesday, United have the perfect opportunity to bounce back and we've examined they key men who need to buck up their ideas.

Paul Pogba

Pogba initially found the form of his United career after Solskjaer took charge, but the team's biggest problem this season has been the midfield's inability to dictate matches. The Frenchman has undoubtedly been partly responsible, stamping his authority far too inconsistently for a player of his talent. Two goals – both of which were penalties – and no assists in his last nine games, Pogba's form has been alarming, particularly those two anonymous showings against Barca in the Champions League. Links with Real Madrid have also resurfaced since Zinedine Zidane's return. Perhaps his head has been turned.

Marcus Rashford

Much like Pogba, Rashford was excellent in the early weeks of Solskjaer's reign, scoring six in the Norwegian's first 10 games at the helm. He has three goals in 13 appearances since. While it's not necessarily a reason for his dip in form, the England international is reportedly stalling on a new contract, hardly helping fan perception in a difficult time. His composure in front of goal has been called into question, while his wastefulness at set-pieces is beginning to grind the gears of supporters. He's undoubtedly talented but looks utterly miserable at the moment, with media reports claiming his attitude is not what it should be.

Romelu Lukaku

Of United's forwards, Lukaku arguably had the most difficult start to life under Solskjaer, with it quickly becoming apparent his attributes weren't ideally suited to the manager's system. Injuries gave him a chance in February and he capitalised with six goals in three games, suggesting he'd managed to adapt, with the new regime wanting him to play with his back to goal less frequently. Recent performances proved that form to be temporary, however. The Belgian is reportedly open to leaving the club at the end of the season and it's difficult to see him being missed if he was to depart.

David de Gea

Probably the only man to have found anything close to world-class form at United since Alex Ferguson's retirement. De Gea has been a great player for United, though it's fair to say he is having easily his worst campaign since his first at Old Trafford. Errors have been made far too regularly compared to his usual standard, including a howler against Barca and more suspect positioning against Everton at the weekend. Coincidentally or not, he's another whose future is in doubt, with contract negotiations apparently going poorly. A social media rallying cry after the Goodison Park defeat at least suggests he cares, but he is not making himself indispensable.

Anthony Martial

United were wise to tie Martial down to a new long-term contract in January given his undoubted potential and market value. The France international had enjoyed a decent start to the season under Mourinho, despite the Portuguese coach reportedly trying to sell him, and that form continued for Solskjaer at first. But since signing his new deal, Martial has scored just twice in all competitions and his displays have left a lot to be desired. He retained his place despite a dire outing at Barcelona and was similarly ineffective against Everton, his runs predictable and unimaginative. He is capable of so much more.