The Manchester derby will tell the boss everything he needs to know about certain stars who are now playing for their futures.
No longer will fans accept members of the squad hiding behind a manager – David Moyes, Louis van Gaal and Jose Mourinho have all come and gone.
Under Solskjaer in his interim stint for three months, United were a changed team – they played for each other and quality shone through in the positive results.
But the end of their record-breaking nine-game winning run away from home has coincided with a huge slump in form, as a group and for many individuals too.
United legend and pundit Gary Neville refused to name names following Sunday’s humiliating 4-0 drubbing at Everton, where Solskjaer apologised to travelling fans at Goodison Park on their behalf.
The fed-up ‘Baby-faced Assassin’ truly cut the cord to his players in his post-match press conference, suggesting some did not care enough.
Supporters, and club chiefs, are fully behind Solskjaer, so the stars at his disposal must now grow up and take responsibility.
The lack of consistency is now deemed unacceptable, with a top-four place now in the balance and United in danger of ending their season with nothing – not even Champions League football to look forward to next season.
“The drop in form of United’s world-class No.1 has arguably been the most alarming of all”
Ahead of the visit of Pep Guardiola’s title-chasing City tonight, Starsport looks at those individuals who are playing for their futures in Manchester.
David de Gea:
The drop in form of United’s world-class No.1 has arguably been the most alarming of all.
Spain international De Gea has been one of few reliable figures in the side in recent years, but he has endured one of the worst campaigns since his 2011 arrival at United.
The Red Devils have conceded 48 top-fight goals already this term – the most they ever have in a single Premier League season.
De Gea has made high-profile, costly errors between the sticks, most recently at Everton where he inexplicably dived far too late for Gylfi Sigurdsson’s long-range effort to make it 2-0.
His contract saga has been an unwelcome distraction for some time now, with the long-term Real Madrid target’s deal still set to expire in 2020.
De Gea’s reported £350,000-a-week demands for parity with United’s top earners, where he would be second to just Alexis Sanchez, seem particularly unwarranted now, and he needs a standout performance against City to remind supporters why they named him Player of the Year four times.
The 29-year-old’s upturn in form and steadiness at the back was typical of the impact Solskjaer’s arrival had on certain underperforming players.
Long have United been criticised for their quality at the back, but Smalling made himself Victor Lindelof’s regular partner at centre-half for months.
But the England international is now wavering again and was totally exposed next to Phil Jones at Everton on Sunday.
Only earlier this month was Smalling telling Lionel Messi to “bring it on”.
Should he send the same message to Sergio Aguero, Raheem Sterling and Bernardo Silva tonight, United fans won’t be able to watch.
Smalling only penned a new deal until 2022 in December, but his future in the first XI ahead of a summer where Solskjaer will be desperate to strengthen defensively in the transfer market will be over if City run him ragged tonight.
From hero to zero, supporters pleaded with the club last year to keep hold of the versatile wing-back.
Gareth Southgate revitalised his England career, and the 33-year-old helped the Three Lions reach the World Cup semi-finals in Russia less than 12 months ago.
But he has been found out at the worst of times in recent matches, with performances against PSG, Arsenal, Wolves and especially Barcelona picked out as being nowhere near the standard he set in 2018.
Young signed a new one-year contract with United in February, and he remains a big voice within the group as a club-captain.
However, he will quickly become a veteran last resort in the squad rather than guaranteed member of the matchday squad if he fails to raise his game.
A starting role at right-back is expected tonight after he was benched at Everton and Luke Shaw back from suspension on the opposite flank, and stopping City’s threats down that side including Benjamin Mendy, Leroy Sane, David Silva and Bernardo Silva will be one tall order.
Of the flops from Sunday, Matic perhaps came out of with the least credit of all.
The midfielder has shown this term exactly why Chelsea fans were far from sad to see him go for £40m two years ago.
A strong first campaign at Old Trafford has been followed up with a horrid season where he has more or less lost his guaranteed place in holding midfield.
Even £52m failure Fred would fee he deserves to start ahead of the 30-year-old Serb.
Everton made him look old, slow and far from top-six quality – so if City catch him out for being off the pace tonight, Matic could well be axed come the summer as Solskjaer prepares for a future based on youth.
The big question surrounding Pogba tonight will be: ‘Does he even want to play for his United future?’
His form has returned to that of under Mourinho, and the bright lights of the Bernabeu are in his sights.
Real Madrid are plotting a summer move with Zinedine Zidane overhauling his squad.
And it seems Pogba has lost the fight at Old Trafford once again, with other clubs ready to swoop in the hope the France version of the midfielder can be channeled every game.
Ahead of City’s visit, Pogba was the man to speak out about the Everton embarrassment, what was said in the dressing room and how players can only go out and prove their worth to fans by turning it on against City.
Forgetting the permutations in potentially helping Liverpool win the title, United need simply focus on themselves, and £89m club-record signing Pogba certainly needs to look at himself in the mirror before stepping out onto the pitch tonight.
Few players are poked at as much as Lukaku for failing to show up in big games.
The £75m hitman is barely a guaranteed first XI player anymore, although Anthony Martial and Marcus Rashford’s dips in form mean the latter will probably play from the left or alongside Lukaku tonight, offering the Belgian a chance to prove his worth.
Solskjaer’s philosophy and playing style does not suit Lukaku, but he cannot hide behind that when his levels drop.
The fire should have been there facing his former side at Goodison Park on Sunday, but the striker was a shell of the man who tormented defences while wearing blue.
He goes up against those in sky blue tonight, but Aymeric Laporte cannot be expecting as tough a challenge as that he’s faced against Heung-min Son in recent weeks.
Lukaku could be one of the casualties of the summer overhaul at Old Trafford this summer, but fans will be far from sympathetic if he shows why that’s the case once again against City this evening.
Those who would be playing for a potential future at Old Trafford… if they could get anywhere near the team tonight – Fred, Alexis Sanchez, Juan Mata, Phil Jones, Marcos Rojo, Eric Bailly.