Manchester United: Competitors for Casemiro’s replacement are Anderson, Wharton and Tonali

While United have not ruled out looking abroad in their search for a new core, the club would prefer to try the Premier League.

Deciding to sign proven players would certainly limit United’s options, and ultimately increase the financial resources associated with those deals.

Baleba, Wharton and Tonali are also among the players who have been discussed by United’s recruitment team and will continue to be explored.

An informed source told BBC Sport that United, through an intermediary, had conducted an initial investigation into Brighton midfielder Baleba in recent months.

However, any successful move for the Cameroonian will depend on Brighton’s valuation, which is reported to be £100m.

While United accept that they will have to pay a huge financial outlay to acquire one of their preferred midfielders, whether they are willing to match the kind of fee Brighton will be looking for is questionable.

Crystal Palace’s Wharton is certainly admired at United, but it is unclear whether he fits the type of central midfielder the club are looking for.

Wharton is seen as a player who benefits from having players alongside him in midfield, allowing him to make the passes that have become synonymous with his burgeoning reputation as one of England’s best emerging midfield talents.

Palace have explored the possibility of offering Wharton – who is on a three-year deal – a new contract with a release clause in the hope of securing his future ahead of next season.

Likewise with Tonali, Newcastle have a history of making things difficult for clubs interested in their players. Just ask Alexander Isak and Liverpool.

But there is a suggestion that the Italian midfielder is open to leaving St James’ Park this summer, with his representatives understood to be studying the market to ascertain which clubs might be interested in him.

Outside the Premier League, Atalanta midfielder Ederson is among the players in Europe who club recruiters have identified as having potential.

There is a world in which United will look to sign a No.6, especially if Manuel Ugarte leaves Old Trafford – which is possible this summer – although in such a scenario, a second signing is far more likely to be rotated than a starting midfield signing.

The exits of Rasmus Hoglund and Marcus Rashford expected this summer will help supplement United’s transfer budget, which will also need to expand to include the signings of a left winger and possibly a central defender, although that will depend on the outcome of out-of-contract centre-back Harry Maguire’s talks over a new deal.

But six is ​​set to be the big number to watch.