Gary Neville urged Manchester United to back Ole Gunnar Solskjaer in the transfer market if they are to break into the Premier League's top two.
After battling to finish third in 2019-20, United have only added midfielder Donny van de Beek from Ajax to their squad despite plenty of transfer speculation.
Borussia Dortmund star Jadon Sancho has been heavily linked with a move to Old Trafford, but the Premier League side are yet to complete a deal for the forward.
Former captain Neville said Solskjaer needed backing if United – who finished 33 points behind champions Liverpool last season – were to continue improving.
"A trophy and breaking that top two has to be the next step. I think this year he has to look to break that top two and that's going to be difficult," he said.
"He needs more players and support from the board to do that. If United don't sign any players it won't be down to the manager that they haven't broken into that top two.
"There isn't anybody in the world with that squad that would break that top two in this moment in time and maybe even struggle to compete with Chelsea with the way they've strengthened.
"So this is the moment that Ole, yes he had a difficult start to last season, but I think with what he's done he deserves that backing that the other managers in the last 10 years have been afforded."
United also have questions over their first-choice goalkeeper, with Dean Henderson having returned from an impressive loan spell at Sheffield United to put pressure on the under-fire David de Gea.
While that competition would usually be considered healthy, Neville believes the constant talk over the shot-stoppers could become unhelpful.
"It's never an ideal situation. You're always better having an excellent number one and a quite clear, very good number two. Henderson isn't going to sit around and wait. And every time De Gea makes some mistake we'll be asking, 'Is this Henderson's moment?'
"Certainly when we had a changing goalkeeping situation, say between Roy Carroll and Tim Howard, it was unhealthy as none of them really knew who the number one was. None of them probably felt fully supported – and they always probably felt like they were one mistake away from the other one playing.
"That could happen with De Gea and Henderson. It's going to be a real challenge of Ole's management skills to keep them both happy, because I think that's impossible."
United are due to begin their Premier League campaign at home to Crystal Palace on September 19.