That’s the verdict of ESPN FC pundit Craig Burley.
Ole Gunnar Solskjaer started Rashford, Anthony Martial and Jesse Lingard away at Tottenham on Sunday as the Red Devils secured a precious 1-0 away win at Wembley, with Rashford the goalscorer in the first half.
That extended their winning run under temporary appointment Solskjaer to six straight victories across the Premier League and the FA Cup.
And Rashford, Martial, Lingard and Paul Pogba were all among United’s most impressive performers alongside the excellent David de Gea.
Lukaku was out injured for Solskjaer’s first two games but in the most recent four, only started in a cup clash with Reading in which he scored.
While he has fired further goals against Bournemouth and Newcastle in the league, the 25-year-old has yet to return to the starting line-up with Rashford – who has four goals an assist in five league games under the Norwegian – trusted as No 9 instead.
And Burley fears that Lukaku – despite his tremendous Premier League record with 109 goals in 239 games – will find himself struggling for starts unless Solskjaer’s squad is hit by injury problems.
Burley said: “At times Lingard was through the middle, Martial was on the left, Rashford was on the right and then it was interchangeable.
“Every time, particularly when they were on top, Pogba was right in behind and he was supporting.
“Under Mourinho, when they won it back it was a lump up to Lukaku. If he didn’t hold it up, it was coming back.
“At least now they’re saying, ‘Right we’re going to back our pace up front, whether it be two or three.’
“I tell you what, United with Lukaku in the side now? I just don’t see it. What a perfect foil he is to come off the bench.
“It’s a lot of money to come off the bench. But I wouldn’t even think about putting him in the team because they’re such a fluid team without him in with the front three and their movement.
“At this moment in time barring injury he’s got no chance of getting in.
“With the personnel they’ve got in midfield at the moment they can play a more open game because they’ve got pace.
“They can’t play an open type of game when you’ve got Fellaini and Lukaku in the team because you haven’t got the pace there.
United will hope to extend their improved run of form at home to Brighton on Saturday (3pm) where they will look to equal their longest winning run since another seven-win run across December 2016 and January 2017.