It is one of football’s worst-kept secrets. Adrien Rabiot’s arrival at Barcelona from Paris Saint-Germain appears to be all but a done deal, although they will have to wait a few more months yet to seal the move.Barca have gone so far as to officially confirm their interest, while PSG have already consigned the conflictive midfielder to football exile for as long as he remains at the club.Rabiot is out of contract at the end of the current season, and his current employers are now resigned to seeing him leave for nothing in June. Article continues below Editors’ Picks ‘There is no creativity’ – Can Solskjaer get Man Utd scoring freely again? ‘Everyone legged it on to the pitch!’ – How Foden went from Man City superfan to future superstar Emery out of jail – for now – as brilliant Pepe papers over Arsenal’s cracks What is Manchester United’s ownership situation and how would Kevin Glazer’s sale of shares affect the club? And while the Catalans may still face competition for his transfer – Liverpool are one of the teams reported to be also in the running – they are certainly in pole position to complete the acquisition of a young man whose obvious ability is only matched for his propensity for falling out with those around him.If, or perhaps when, the move is completed, the player will enter one of the world’s most competitive midfields, with a mix of top-class talents, promising youngsters and imperious veterans already ensuring the Catalans lack for absolutely nothing in the engine room.Protagonist in more than a few altercations during his time at Parc des Princes, he will have to shape up and show his very best in order to establish himself as a regular first-teamer in La Liga.Rabiot excels as a box-to-box midfielder, much in the vein of future Camp Nou team-mate Arturo Vidal. Being left-footed, the player also offers a fresh option in that sector to release the ever-dangerous Jordi Alba on the overlap.Tall, strapping and unerring in the pass, at his best he presents an interesting mobile alternative to the more creative Philippe Coutinho on the left of a hypthetical midfield trio.The France international is also capable of sitting further back in midfield, anchoring a three or playing alongside another holding man if Coutinho lines up on the left.That role is of course dominated by the incomparable Sergio Busquets. But Rabiot would provide a useful rotation option for when the midfield maestro is rested or unavailable, and could slot in alongside the promising Arthur in a duo that would not miss a beat in the pass.Rabiot’s biggest question marks revolve around his fragile mental state. Collapses such as that seen in the Champions League last-16 defeat against Real Madrid would not be tolerated at Camp Nou; nor would subsequent public outbursts that painted the player in a less than favourable light.He also refused to be on stand-by for France’s World Cup squad and missed out on the tournament, leading to claims that he was “immature”. Compatriot Ousmane Dembele has faced similar criticisms of his attitude since joining Barca; another problematic dressing room presence would quickly be exposed.No-nonsense Valverde seems to have made progress with Dembele, with the winger responding by proving he has the talent to make headlines on the pitch. Rabiot has the talent too, but wherever he lines up for Barca will have to prove his mentality is also up to scratch at one of the world’s most demanding clubs.