Ole Gunnar Solskjaer will be 'seriously regretting' his failure to replace Romelu Lukaku last summer now that Marcus Rashford is injured, according to Paul Ince.
'If Ole wasn't already regretting letting Romelu Lukaku go, he seriously will be now,' former United midfielder Ince told Paddy Power.
'I'll be the first to admit that I had a go at him at times, and he can't retain the ball, but you do get 20-25 goals a season from him.
'United let him go without replacing him and now they're paying the price. Hindsight is a wonderful thing but, really, Ole should never have let him go.'
Solskjaer hinted that he may have to dip into the transfer market during the closing days of this month's window to try and make up the shortfall of goals now Rashford is injured.
United failed in their pursuit of the Norwegian wonderkid Erling Braut Haaland, who opted to sign for Borussia Dortmund, something Ince has described as 'embarrassing.'
'A new signing in January has become a must,' he said. 'It's not that they need to - they absolutely have to.
'It kind of makes Erling Braut Haaland even more embarrassing and a pain in the arse than it already was, especially after we saw his debut hat-trick [against Augsburg on Saturday].
'Because if they don't sign someone, who's going to get you goals?
'We saw the sitter that Anthony Martial missed against Liverpool. It's simply not good enough. He should be burying that, if that had fallen to Rashford I'm confident that would've been a goal.
'With Rashford out, you can't trust Martial will make up those goals. Mason Greenwood is great, but he's young, untried and untested. You can't put that level of pressure on such a great player.'
United continue their attempt to finish in the Premier League top four with a home fixture against Burnley on Wednesday night. They are currently five points behind fourth-place Chelsea.