Paul Pogba has completed his return to Juventus from Manchester United on a free transfer.

The Frenchman, 29, began his senior career at Old Trafford before moving to the Italian giants in 2012 after running down his contract.

As Pogba once again makes the switch from Manchester to Turin, we take a look at what went wrong for the mercurial midfielder.

Record-breaking return

Pogba's second spell in the Premier League began with huge expectations in 2016 as the Red Devils splashed a then-world record £89million to land a man they had lost for nothing four years earlier.

The United academy graduate had excelled at Juve, bagging 34 goals in 178 appearances and won eight major trophies, including four Serie A titles.

By contrast, in the six years since, he has just a Europa League and League Cup to show from his time in Manchester, both achieved in the 2016-17 campaign.

He operated in various positions across central midfield, including defensive and advanced roles, as well as playing as a false nine at times under Ralf Rangnick last season.

Plagued by injury, public fallouts with managers and a difficult relationship with United supporters, it is fair to say the huge investment did not go as planned.

Mou meltdown

Pogba’s statistics were not groundbreaking in his first season back at the Red Devils, registering nine goals in 51 appearances, but clinching a double trophy success under Jose Mourinho offered cause for optimism.

United's creator-in-chief netted the opener in the Europa League final and was named Player of the Tournament as Mourinho's men overcame Ajax in the Stockholm showpiece.

But Pogba's relationship with his Portuguese coach turned sour following France's World Cup triumph in 2018.

Buoyed by Les Bleus' victory, the Paris native started the season well but soon lost his starting place and was branded a "virus" by Mourinho, who was sacked in December 2018 and replaced by Ole Gunnar Solskjaer.

The Norwegian's appointment coincided with an upturn in Pogba's form, finishing the campaign with 22 top-flight goal involvements — his best tally in a United shirt — and he was named in the PFA Team of the Year.

Ole at the wheel

When it looked like Pogba would finally kick on and begin to develop into an integral part of Solskjaer's side, an injury-plagued 2019-20 season stunted any hopes of continued improvement.

Pogba struggled to fully bounce back in 2020-21, a campaign heavily disrupted by the coronavirus pandemic.

It seemed like he had finally turned a corner at the start of last season however, as he picked up four assists against Leeds in the opening game and another at Southampton the following week.

United fans began to feel excited by the prospect of their No6 orchestrating a title challenge from the centre of the park.

But a straight red card in a humiliating 5-0 home defeat to Liverpool brought widespread criticism and a hamstring injury picked up on international duty in November 2021 kept Pogba sidelined.

And later that month, Solskjaer was sacked thanks to another dismal defeat, this time at Watford.

What might have been

Despite many glimpses of his undoubted ability, fluctuating performances dogged Pogba throughout his United career — epitomising the wildly differing fortunes of the Solskjaer era as a whole.

A brace at Manchester City in April 2018, a goal and assist in an FA Cup fifth-round victory at Chelsea in February 2019 and a decisive strike against Milan at the San Siro in March 2021 proved what he was capable of.

But the midfielder was unable to regularly show his best.

As results deteriorated last term, it was a clear sign that Pogba's United career and the wider project under interim boss Rangnick needed to end.

Pog-back

A return to Juventus is likely the best option for Pogba, where he can feel some love from a Bianconeri fanbase who previously showed such affection for their midfield ace.

Indeed, Pogba's move back to Serie A will benefit all parties as United have now significantly reduced their wage bill and new boss Erik ten Hag can target players for his system.

Juve, meanwhile, have added world-class experience to a talented squad featuring Dutch defender Matthijs de Ligt, prolific forward Dusan Vlahovic — both 22 — along with 24-year-old Euro 2020 winners Manuel Locatelli and Federico Chiesa.

Working once more under the tutelage of former boss Max Allegri, there is still plenty to come from the enigmatic star.