Ole Gunnar Solskjaer has five games left in the Premier League season to prove conclusively that the club's hierarchy did not act too hastily in making him Jose Mourinho's permanent successor last month.
After a spectacular start as caretaker manager of the club, in which he won his first eight games and lost just one of his opening 17 matches in charge, United have since suffered a precipitous drop in form.
Five defeats have come in United's last seven games, a run which has seen them exit the FA Cup and Champions League and left a top-four finish in serious doubt.
Since former United striker Solskjaer was appointed to the position on a permanent basis in late March, United have won two of five games, unconvincing 2-1 home victories against Watford and West Ham United, and now face a potentially pivotal week in the league campaign.
"When we came in, on the 19th of December and where we're at now, I think anyone would have taken that now we've got five games to see if we can finish it off," Solskjaer said.
United's season ends with a visit to already-relegated Huddersfield Town and a home game against Cardiff City - both of whom may have nothing to play for by the time the season reaches May.
But Sunday sees United visit Everton, conquerors of Chelsea and Arsenal in their last two home games, at the start of a week in which they also host title contenders City in the Manchester derby and then welcome Chelsea to Old Trafford at the weekend.
Those three games look likely to determine whether United will cement one of the two Champions League places for which they are competing, along with Chelsea, Arsenal and Tottenham Hotspur.
All three London clubs also have one eye on European semi-finals - with Spurs having reached the last four of the Champions League in spectacular fashion against City in midweek and Arsenal and Chelsea both advancing in the Europa League.
United, meanwhile, were emphatically knocked out of the Champions League quarter-finals at Barcelona.
Meanwhile, Ainsley Maitland-Niles believes Arsenal's run to the Europa League semi-finals will aid their Premier League top-four push against Crystal Palace on Sunday.
Unai Emery's side advanced to the last four on Thursday as Alexandre Lacazette's goal sealed a 1-0 win in Napoli and a 3-0 aggregate success.
Arsenal face Valencia in the semi-finals, with Emery aiming to win his fourth Europa League title and seal Champions League qualification in the process.
That would be an uplifting conclusion to Emery's first season with Arsenal, but if they fall short in the Europa League, the Gunners still have another route to the Champions League via a top-four finish in the Premier League.
Currently in fourth place above Chelsea on goal difference, Arsenal have no margin for error in the league, but defender Maitland-Niles says his team have matured as a result of their European exploits and are now better at closing out matches.
"It's a tough league in England. We're learning different methods in Europe because sometimes we need to be more like the foreign teams and just grind out results. It's going well at the moment," he said.