Manchester United were mocked last summer when they spent £89 million on a player who left Old Trafford for virtually nothing four years earlier.

However, after what he achieved during his four seasons at Juventus, United were left with no choice but to break the world transfer record in order to bring Paul Pogba back to Manchester.

Despite criticism from outsiders, United weren’t remotely concerned. All that mattered to everyone associated with the club was that they’d acquired the services of the best young central midfielder on the planet.

After finishing this season sixth in the Premier League table - their final league standing has been confirmed following Arsenal’s 2-0 win over Sunderland on Tuesday night - United boss Jose Mourinho is expected to strengthen his squad in multiple positions this summer.

Top of the agenda is a new striker. Antoine Griezmann is understood to be Mourinho’s number one target, although there’s still a lot of work to done in order for that deal to happen. James Rodriguez, meanwhile, is unlikely to end up at Old Trafford. Although Real Madrid want the Colombian out of the Bernabeu, a new attacking midfielder isn’t a priority for Mourinho.

Aside from a new goalscorer (potentially Griezmann, but possibly Romelu Lukaku or Andrea Belotti), United are also in the market for a new centre-back.

And it appears their search is already over.

United's first summer signing is...

According to the Daily Mail, United are set to replicate last summer’s transfer activity by spending a huge sum of money on a player who was previously on the books at Old Trafford.

Burnley defender Michael Keane is set to re-sign for the Red Devils in a £25 million deal.

Louis van Gaal allowed the central defender, now 24, to leave United for just £2 million back in January 2015.

But United included a 25 per cent sell-on clause, meaning they will need to pay less money for Keane than any of their rivals would have done had they won the race for his signature instead.

Keane, who first joined the Red Devils aged 11, is expected to quadruple his £25,000-a-week wages once he re-signs for his former employers.

Chris Smalling could leave United

His return could spell the end of Chris Smalling’s career at Old Trafford. The England international is reportedly disillusioned with life under Mourinho after being singled out in public on several occasions by the Portuguese tactician.

Rio Ferdinand wants Keane back at United

Whether United fans believe Keane is an upgrade on Smalling is unclear, but Rio Ferdinand recently admitted he would love to see the former return home.

“I think the moment he found out he (Keane) was going to leave Manchester United – every kid’s dream in that area is to play for Manchester United – so to leave the club was a huge wrench for him,” Ferdinand was quoted as saying by The Sun.

“But it allowed him to go and spread his wings and bloom really and become the player he is now.

“At Manchester United he wasn’t afforded that opportunity, for whatever reason.

“You look at the likes of Pogba… he’s gone away and come back now and become a huge star. Michael Keane, he could do that himself.”