The final week of the European transfer window is sure to be dominated by the future of the world's most expensive player as speculation over Neymar's position at Paris Saint-Germain continues to intensify.

La Liga giants Barcelona and Real Madrid are both understood to be interested in the Brazilian forward, who is desperate to return to Spain following two tumultuous years in the French capital.

Barcelona are thought to be leading the race after stepping up their pursuit in recent days, with rumours of a big-money offer plus Ousmane Dembele.

Here, Sports Mole looks at how Ernesto Valverde could set his side up should Neymar complete his feted return to Camp Nou.

The first dilemma for Valverde to solve upon the possible arrival of Neymar will be how to fit him into the team alongside Lionel Messi, Luis Suarez and Antoine Griezmann.

The quartet would give Barcelona arguably the most dangerous attack in world football, although to fit them all into the same starting XI Valverde would likely have to adapt his preferred 4-3-3 formation.

Messi remains undroppable and, should the 4-3-3 system prove to be concrete, then it would likely be a straight shootout between Suarez and Griezmann for the central striking role.

Neymar, Suarez and Messi formed a deadly partnership during their previous time together, but Griezmann got off the mark with a brace at the weekend and will expect to start regularly following his £107m arrival from Atletico Madrid.

A 4-2-3-1 formation appears to be the most suitable system for all four to be included, and that would also allow Barca to start both Sergio Busquets and Frenkie de Jong in their preferred roles, although Arthur, Arturo Vidal, Rafinha and Ivan Rakitic provide further depth in the middle of the park.

The centre-back partnership of Clement Lenglet and Gerard Pique is now Valverde's preferred duo, while Jordi Alba remains first-choice left-back despite the arrival of Junior Firpo and Marc-Andre ter Stegen is the undisputed number one.

The only position seemingly up for grabs in the back five is therefore right-back, where Sergi Roberto and Nelson Semedo will battle it out should the latter not be included in the deal to bring Neymar to Camp Nou.