The club signed only Marouane Fellaini during last summer’s transfer window, on deadline day, but have already splashed £60million on Luke Shaw and Ander Herrera from Southampton and Athletic Bilbao respectively this time around.
New manager Louis van Gaal has also been linked with the likes of William Carvalho, Angel Di Maria, Memphis Depay and James Rodriguez as the club undertakes a significant recruitment drive to improve on last season’s seventh-place finish under David Moyes.
And Sky Sports expert Yorke says it is imperative his former club invests heavily if they are to stand a chance of getting back into the Champions League.
He told Sky Sports News: “We know there are six or seven players that they’re trying to buy and we are seeing the aggressiveness of Manchester United splashing the cash.
“And they need to. Last season was a bit of a disaster for Manchester United from that point of view and I don’t think they can afford to be left behind like they have done,
“They did not qualify for the Champions League and were not even being on the front of competing for the Premier League.
“That was a huge blow and to be able to compete with the likes of City, Liverpool and Chelsea – who you’ve seen are spending a lot of money as well – you have to splash the cash.
“That’s certainly what Manchester United are trying to do at this time.”