Record buy, statement signing, tactical conundrum: Juan Mata is many things. The first footballer to cross the great divide between Chelsea and Manchester United since Juan Sebastian Veron made the opposite journey in 2003 is, like the Argentine was more than a decade ago, a flair player whose presence can prompt managers to reshape a side.
Jose Mourinho opted to bench Mata instead. Having spent £37 million on him, David Moyes is unlikely to follow suit, but he is confronted with a dilemma - how does he fit the Spaniard, Wayne Rooney and Robin van Persie into the same side? It is an altogether more pleasant problem than wondering whether to play Ashley Young, Antonio Valencia or both. As long as either of United's star strikers is absent, the answer is easy: behind the other in a 4-4-1-1 or 4-2-3-1 formation. When both are back, it becomes more complicated.
Mata does not fit naturally into a 4-4-2 system. Instead, other tactics are required. His past shows his versatility - or, some might say, his capacity to occupy the same areas despite having supposedly different starting positions.
Pre-Mourinho, Mata's Chelsea career fell into three phases. The first, under Andre Villas-Boas, came on the left of a slightly unusual 4-3-3 formation. Didier Drogba and Fernando Torres alternated as the lone striker but the right-sided attacker, Daniel Sturridge, was a centre-forward by trade and Mata, beginning from the left, did not operate as an out-and-out winger, either.
His touch map from a game against United, the remarkable 3-3 draw in February 2012, shows that he did not play in a fixed position. Mata set up one goal that day, with a free-kick that David Luiz converted, and scored another with a spectacular volley from eight yards.
Given the lack of goals from United's wide players in the Premier League this season - Valencia, Young, Nani and Shinji Kagawa have only contributed three between them - the Spaniard ought to offer more potency from the flanks. The problem for United of trying the same system, apart from Moyes' age-old preference for 4-4-1-1, is that there is no central support act to the lone striker: no No. 10, the preferred role for both Mata and Rooney.
Chelsea's improbable run to Champions League glory under Roberto Di Matteo was more about their resilience and rearguard actions than Mata's ability; whether as a No. 10 or a left winger, his job encompassed plenty of defensive duties and he hardly flourished; indeed the miracle in Barcelona occurred after Mata had been replaced by the more energetic Salomon Kalou.
Their recalibration as an attacking force last season suited the Spaniard better. He was installed as the No. 10 by Di Matteo and retained that role under Rafa Benitez. He was flanked by Oscar and Eden Hazard, like-minded creators, and their licence to switch positions is underlined by Mata's touch map in the 4-2 win against Villas-Boas' Tottenham, when he scored twice and created one goal.
His ability to find team-mates in the final third, where he completed 16 out of 20 passes, and his capacity to pick out colleagues in a packed penalty box was evident. Again, it ought to make United more prolific and there was a marked statistical difference with his Old Trafford counterparts last season: he finished it with 20 goals and 25 assists in all competitions, dwarfing the contributions of their attacking midfielders. Moyes' United, meanwhile, have been criticised for their over-reliance on the flanks when attacking; Mata's record shows he can fashion chances from the middle of the pitch if a manager is willing to build a team around him.
If Moyes were to configure his side the same way as Chelsea - and it would suit his central midfielders, who lack the power to burst forward, to be spared attacking responsibilities - Adnan Januzaj and Kagawa would be logical allies for Mata. When Rooney and van Persie are available again, however, one would have to make way. The Japanese is the probable fall guy, which takes Moyes back to the original issue: Is Rooney or Mata given the consolation prize of a place on the left? Given the Englishman's pivotal part in Moyes' plans and reluctance to operate on the sides, the likelihood is the Spaniard will become the expensive, ersatz wide man.
It seemed significant that the out-and-out wingers, Valencia and Young, did not start against Sunderland on Wednesday. Moyes' Everton rarely featured touchline-hugging players on either flank; instead they were midfielders by trade, forever looking inward while creating room for overlapping full-backs to advance outside them. One of many reasons Kagawa has frustrated is that he has failed to replicate Steven Pienaar's influence as the inventor in the inside-left channel.
Yet it is a ploy that is dependent on two things: a full-back with unlimited energy, a la Leighton Baines - and while, at his peak, Patrice Evra definitely belonged in that category, his legs are beginning to let him down - and a technical talent who is willing to double up with the defender in his own half. It is a flaw in the game of one Spaniard who prefers to be a No. 10 but is accommodated in a wider berth. Defensively, Mata may have to show he isn't another Santi Cazorla. The fact that Mourinho has sold him suggests he has his doubts.