Manchester United only need "one more signing" to challenge for the title again, according to Phil Neville.
United have been starved of success at the very highest level since the departure of legendary former manager Sir Alex Ferguson in 2013.
The Red Devils haven't come close to winning the Premier League or European Cup in the last seven years, with Manchester City, Liverpool and Chelsea all moving above them in English football's pecking order.
However, Ole Gunnar Solskjaer has invested smartly in the transfer market over the past year in a bid to revive past glories, and results have improved significantly in the second half of the 2019-20 campaign.
Daniel James, Harry Maguire, Aaron Wan-Bissaka were all brought in last summer, before United forked out €55 million (£50m/$62m) to sign Bruno Fernandes from Sporting in January.
Odion Igahlo also arrived at Old Trafford on loan in the winter market, and Solskjaer has watched his new squad gel over the course of a 14 match unbeaten run which stretches back to February.
The Red Devils are now pushing hard for a return to the Champions League, with FA Cup and Europa League honours still up for grabs, but they still find themselves a long way behind Liverpool and City in the top-flight standings.
Neville thinks that gap can be closed significantly if Solskjaer adds one more key player to his ranks, as long as Paul Pogba ignores links to Real Madrid and remains at Old Trafford beyond the summer.
The ex-United midfielder told Premier League Daily how close Solskjaer is to completing a rebuild in Manchester: "I think one more signing.
"You think about Liverpool signing [Virgil] Van Dijk and Alisson in goal.
"One or two more signings or [Paul] Pogba and one more signing playing to their absolute best. I think United can get closer."
Pressed on which area United need to reinforce when the transfer window reopens, Neville responded: "Centre-back, you look at the impact Van Dijk had.
"Maguire has had a really strong impact but another real strong centre-back.
"They’ve still got to be defensively sound. One more signing and United can challenge."
The former England international also admitted that another striker could walk through the doors at the Theatre of Dreams later this year, while insisting that Marcus Rashford won't be permanently stationed on the left-wing.
Neville added on Solskjaer's potential attacking plans: "He'll want Rashford to develop into a centre-forward, 100 per cent.
"But I think Rashford, Martial and Greenwood like to play in and around a centre forward.
"It wouldn't be a surprise if they still went into the transfer market and bought a centre forward.
"But with Pogba and Fernandes and their type of creativity, Martial and Rashford and Greenwood will get better service.
"It means that when they play a little loose, they've got someone in Fernandes who will play that killer pass."