Where will Pogba fit in at Manchester United?

Wayne Rooney could give way?

What you need to know:

But while Pogba's place in the team will be secure, the nature of his role could determine whether he flops or flies

With Paul Pogba poised to complete his record-breaking return to Manchester United, manager Jose Mourinho must figure out how best to fit the France midfielder into his star-studded starting XI.

Pogba excelled at Juventus on the left-hand side of midfield in a 4-3-3 formation, but Mourinho appears set to adopt a 4-2-3-1 system in his first season at Old Trafford.

It would oblige Pogba to adopt a deeper position, which could compromise Mourinho's ability to get the very best out of him.

"Used in the right way in this United team, Pogba's long-range shooting and ability to get into the box will make him a massive threat," says former Liverpool midfielder Danny Murphy, now a BBC pundit.

"He could be the difference between United winning the title or not."

Pogba was expected to undergo a medical at United on Monday as he closes in on a reported 89 million pounds ($116.4 million, 105 million euros) return to the club he left in 2012.

The 23-year-old wore the coveted number 10 shirt in his final season at Juventus, but he will have to earn the right to be considered the chief creative talent at United.

Wayne Rooney is due to start the season in the number 10 role.

New signing Henrikh Mkhitaryan can also play as a central playmaker and Mourinho has further options in the shape of Spanish midfielders Juan Mata and Ander Herrera.

In any case, as Oualid Tanazefti, the man who brought Pogba to his first club, Le Havre, told French sports daily L'Equipe during Euro 2016: "Number 10 is really not his position."

Were Mourinho to make putting Pogba in his optimum position a priority, by reverting to a 4-3-3 system, it would create dilemmas elsewhere in the team.

Mourinho has already vowed Rooney will not play in midfield, as he has for England, so a move to 4-3-3 would leave the United skipper vying with Zlatan Ibrahimovic for the lone striker's role.

Deschamps deliberations
Pogba's principal strengths -- dribbling, passing and long-range shooting -- depend on him having the freedom to get forward.

He provided a league-leading 12 assists in Serie A last season, but France coach Didier Deschamps struggled to find the right role for him during Euro 2016.

He initially started on the right of a midfield three, but in an effort to replicate his role at Juventus, Deschamps experimented by moving Pogba to the left and shifting Blaise Matuidi to the right.

However, a switch to 4-2-3-1 at half-time of France's last 16 encounter with the Republic of Ireland in Lyon saw Pogba drop back to the right-hand side of a midfield two alongside Matuidi.

He played there for the rest of the tournament, sparkling only intermittently as the hosts reached the final, and Deschamps admitted that it was not his ideal role.

"I don't think any of you would say that the best position for Paul is in front of the defence alongside Blaise," he told reporters.

Pogba's coach at Juventus, Massimiliano Allegri, believes that he will end up playing as a holding midfielder, but not for a few years yet.

When Pogba left United four years ago, it was because his path to the first team was barred by players like Michael Carrick, Paul Scholes, Ryan Giggs and Park Ji-Sung.

Now it is he who will be putting squad-mates in the shade.

Bastian Schweinsteiger is already thought to have been frozen out by Mourinho.

With either Carrick or Morgan Schneiderlin likely to partner Pogba in midfield, Marouane Fellaini and Herrera will also be bumped down the pecking order.

But while Pogba's place in the team will be secure, the nature of his role could determine whether he flops or flies.