Manchester United manager David Moyes may need to spend £200m this summer to turn things round at Old Trafford after sinking to new depths at Olympiacos in midweek, according to West Ham boss Sam Allardyce.
Moyes is under pressure to improve performances and results as a matter of urgency after a dreadful run since the turn of the year, which continued in the Champions League on Wednesday night with a 2-0 defeat in Greece.
Allardyce has insisted that United are in a transitional period that was unavoidable regardless of Moyes because of the squad's make-up, before conceding that their "bewilderingly poor" display in Athens threw under the spotlight their stark need for a major overhaul during the close season.
The Hammers boss told the Evening Standard: "Just when it seemed Manchester United were settling down, following their win over Crystal Palace, they turned in what David Moyes freely admitted was a bewilderingly poor performance against Olympiakos.
"This has been a tough learning curve for David and he will be assessing how he attacks the job in the future. He knows he must re-establish United to where they need to be.
"David is left with having to make more decisions about players at the end of the season than he expected. It looks like he will have to plan a rebuild and for a club like United, that could mean an outlay of £200million."
Moyes has a welcome weekend away from the spotlight as United have no Premier League fixture until March 8th, due to Manchester City's participation in the League Cup final.
United are a whopping 11 points behind Liverpool in the fourth and final Champions League qualifying spot, facing a huge uphill task to earn a place in Europe's premier club competition next season.
Without a dramatic improvement in league form United's only route back into the tournament next season will be lifting the European Cup itself, although that also looks a tall order given their first-leg scoreline against Olympiacos.