Manchester United's meek capitulation at Newcastle underlined the importance of midfield duo Casemiro and Christian Eriksen.
The humiliating 2-0 defeat, which put a fresh dent in United's top-four hopes, also confirmed their understudies are not up to the task.
Scott McTominay and Marcel Sabitzer are simply not adequate replacements and saw their inadequacies brutally exposed in Sunday's humiliation. While there was mitigation for Fred, who only came on for the last 10 minutes, he too is vulnerable ahead of a major summer exodus at United under boss Erik ten Hag.
Casemiro still has to serve two games of a four-match ban for a second red card this season, meaning he will not return domestically until April 16, away to Nottingham Forest.
Eriksen, meanwhile, has been out since late January with ankle ligament injury, with United having badly missed his unique creative influence during his enforced lay-off.
Without Casmeiro and Eriksen, United lack balance in midfield, their combined absence reflected in a run that has seen Ten Hag's side win just three of their last nine Premier League games.
Six weeks ago, third-placed United held an eight-point advantage over fifth-placed Newcastle in the race for a top-four spot and looked certainties for an immediate return to the Champions League.
They beat Newcastle in the Carabao Cup final, to end the club's six-year trophy wait, and dumped runaway La Liga leaders Barcelona out of the Europa League in a double-header play-off.
Now, after three league games without a win, including a humiliating 7-0 defeat at arch rivals Liverpool - which decimated their goal difference - United have been overtaken by Newcastle.
Against that backdrop, winning the Europa League has become imperative, with a Champions League spot through a top-four Premier League finish now in jeopardy.
No Champions League means United can forget signing England duo Harry Kane and Jude Bellingham, Ten Hag's top transfer targets this summer. The current run is the biggest crisis Ten Hag has faced since beginning his United tenure with defeats to Brighton and Brentford, to sit bottom of the table.
Ten Hag's selection and deployment of the personnel at his disposal against Newcastle also warranted criticism. Bruno Fernandes and McTominay swapped positions, the dropping back into midfield, the latter playing as a No.10.
The decision backfired, while Ten Hag's decision to introduce Jadon Sancho and Anthony Martial – the latter losing the ball in the build-up to Newcastle's opener and then making zero effort to win it back – was misguided.
The reality is United are a handful of world-class players short of being able to compete for the title again. McTominay, Martial, Harry Maguire, Anthony Elanaga, Donny van Beek and on-loan striker Wout Weghorst all are all likely to be offloaded this summer for the next phase of Ten Hag's rebuild.
Ten Hag faces some big calls, but the immediate objective is to secure a Champions League spot – for without one, United's undoubted progress under him this season could come to a juddering halt.
