The Netherlands international looks set to sign for the Red Devils for around £14 million after the club agreed a fee with Ajax for the versatile Blind.
Blind will arrive to a defensively threadbare squad and the new man will be expected to immediately contribute to a side that has looked weak in their three games so far this season.
Louis van Gaal is yet to win a game in charge of the Red Devils and their opening day defeat to Swansea City was followed up by a 1-1 draw away to Sunderland before their 4-0 humiliation to League One side MK Dons in the Capital One Cup on Tuesday.
Blind is reportedly set to undergo his medical this weekend, but ex-United star Scholes has his doubts about the move.
Speaking to BT Sport, he said: "Is he a defensive midfielder? I think he can play left wing-back, but can he play left centre-half? I’m not sure. I think the only place he is going to play is midfield. We’ve got a few of these left-footed players now.
"I’m not too sure what position he’s going to play in. I don’t think he’s strong enough for a left-back in England. The only place where we can seem to get him into the team is central midfield. He’s a very good footballer, don’t get me wrong, but is he the answer centrally? We’ll have to wait and see.
"Yes. He’s coming in. We don’t really know what position he is. I don’t think United are in a position to be taking risks on people - is he a left-back? Is he a central midfield player?
"I think they need proper central midfielders. There’s been a few on the market and they obviously haven’t fancied them or not been able to get them, and now they’ve got someone who’s maybe a bit-part central midfield player."
The arrival of Blind will take United's spending this summer to around £150 million following the arrivals of Luke Shaw, Ander Herrera, Marcos Rojo and Angel di Maria.
Argentina international Di Maria arrived earlier this week for a British-transfer record of £59.7 million and much will be expected of the former Real Madrid star.