Sheffield United now face a rebuild in the Championship with the club in crisis on and off the field.
Wilder believes the impact of the pandemic had a particularly profound effect on the Blades' dip in results.
Premier League: Manchester United hit back to sink Tottenham Hotspur; Jesse Lingard lifts West Ham into 4th
Ole Gunnar Solskjaer's Manchester United trailed to Son Heung-min's first half strike, but United scored three times after the break through Fred, Edinson Cavani and Mason Greenwood.
Premier League: Man City move closer to title with win over Leicester; Liverpool thump Arsenal, Tuchel suffers first Chelsea loss
Manchester United can close the gap with a win against Brighton on Sunday in the first of two games in hand, but it is only a matter of time before Pep Guardiola's men celebrate their third title in four seasons.
Leicester are chasing a double over the leaders after a stunning 5-2 win at the Etihad Stadium in September. Former City striker Kelechi Iheanacho is in fine form after scoring seven goals in his last four games for Leicester.
Sheffield United seem destined for a return to the Championship as they sit bottom of the table, 12 points adrift of safety with just 10 games left to play.
Premier League: Manchester United lose ground on leaders City with fog-bound Crystal Palace draw, Burnley hold Leicester
The stalemate at a foggy Selhurst Park was United's third successive goalless draw in all competitions ahead of Sunday's Manchester derby against City, who are on a record-breaking 21-game winning streak.
Premier League: Chris Wilder laments 'incredibly tough situation' as Sheffield United face relegation
But this campaign has been a real struggle and, with 12 games remaining, they are rooted to the bottom of the table, 15 points adrift of fourth-from-bottom Newcastle.
Premier League: 'Written off' Liverpool still ready to fight, says Jurgen Klopp after 2-0 win at Sheffield United
The English champions' title defence has been decimated by injuries and they face a battle just to qualify for next season's Champions League via a top-four finish.
Premier League: VAR penalty controversy leaves Manchester United frustrated after draw against Chelsea; Liverpool end losing streak
Liverpool took advantage of dropped points for Chelsea to move within two points of the top four by ending a four-game losing streak with a 2-0 win at Sheffield United.
After exactly 1,000 minutes without finding the net, Timo Werner ended his Premier League goal drought.
Premier League: Chelsea boss Thomas Tuchel not worried by Timo Werner’s goal drought, hails effort in Sheffield United win
Werner set up Mason Mount's opener and won the decisive penalty, converted by Jorginho, as Chelsea closed to within a point of the top four with a third win in Tuchel's four games in charge.
Premier League: Sam Allardyce's proud record at risk after 'damaging' West Brom defeat against Sheffield United
With just one point from their last 12 West Brom are nine points adrift of safety - having played a game more than fourth-from-bottom Brighton.
Manchester United's first victory in three league games means they are behind leaders Manchester City only on goal difference.
Premier League: Ole Gunnar Solskjaer claims match delegate in Sheffield United loss admitted to getting key decisions wrong
The 2-1 defeat last Wednesday ended United's 13-match unbeaten league run, leaving Solskjaer frustrated by the decisions that allowed Kean Bryan's opener to stand before Anthony Martial's strike was ruled out.
Premier League: Manchester United, Arsenal play out goalless draw; Manchester City claim three point lead at top
Gabriel Jesus scored the only goal inside the first 10 minutes at the Etihad as Manchester City extended their winning run to 12 games in all competitions.
Guardiola's men, who host Sheffield United on Saturday, will hope to avoid the fate of their Manchester rivals, who lost 2-1 at home to the bottom side in midweek.
Premier League: Manchester United slams 'mindless idiots' after Anthony Martial, Axel Tuanzebe face racist abuse online
The 2-1 defeat to Sheffield United sparked a torrent of online invective aimed at Manchester United's players, including racist abuse aimed at defender Tuanzebe and forward Martial.
Premier League: ‘Time to stand up and be counted,’ says Harry Maguire after Manchester United’s shock loss to Sheffield United
Maguire cancelled out Kean Bryan's opener with a powerful header in the second half but Oliver Burke scored the winner for the visitors after United failed to clear.
Premier League: Chris Wilder wary of claiming 'the escape is on' after Sheffield United's shock win over Manchester United
The Blades' 2-1 win on Wednesday put a huge dent in United's hopes of winning their first Premier League title since 2013 and gave them a huge morale boost in their battle to avoid relegation.