Manchester United face another £100 million blow out if they fail to finish in the top four this season.

That figure includes loss of earnings as a result of missing out on Europe's most lucrative tournament and the additional sums the club will have to stump up to lure players to Old Trafford without the carrot of the Champions League, says the Sunday Mirror.

It would be the second time in three years that United have failed to qualify for the Champions League, with this season's group stage elimination costing them an extra £20million.

That would put the conservative cost of van Gaal's regime at £120million if results go against his side and Manchester City maintain their fourth place spot this afternoon.

“You're talking £50million from missing out on the Champions League and another £50million on additional acquisitions as a result of not being able to offer Champions League football," says Rob Wilson, football finance expert at Sheffield Hallam University.

“A good example of that is when Man United signed [Angel] Di Maria and [Radamel] Falcao in the summer of 2014.

“They were signed on big wages and, in Di Maria's case, a huge transfer fee that was probably more than it ought to have been because of no Champions League football."