The next few weeks will form a fascinating part of the career of Real Madrid and Brazil left-back Marcelo.
That is a sentence that might seem strange when seem from the perspective of 2005 and 2006, when he made his first-team breakthrough with Fluminense, and enjoyed a goal-scoring debut with Brazil. True, he did all of this as a left-back, but at the time there was a consensus -- emphatically argued by his club coach Oswaldo de Oliveira -- that he would end up as a midfielder.
The rationale was clear: Marcelo is much better going forward than defending. But more than a decade later, he is still very much a left-back, has played there for years in the world's best club side and will do so for Brazil in Russia. Though it is very possible to imagine him rounding off his career with a spell back in Brazilian club football as a roving attacking midfielder, history will remember him as a left-back. And in terms of the national team, how history will remember him has a lot to do with what happens in Russia.
He is undoubtedly one of the world's great attacking full-backs, and he played a full part in Real Madrid's latest Champions League triumph. That wonderful Gareth Bale overhead kick came from his cross. True, it took a slight deflection before it reached Bale, but it came off Marcelo's weaker right foot -- a testament to the range of attacking options that he offers. He can go outside and cross from the byline, he can cut into the penalty area on the diagonal and shoot, he can shoot from range, he can cross off either foot. He is a remarkable attacking asset.
Defensively, there are two problems. One is his inability to be in two places at the same time. When he pushes forward, there is inevitably the risk of leaving a hole behind him. But that is much more a problem for the coach than it is for Marcelo. A team that does not take advantage of his forward surges is guilty of a grievous waste. It is up to the coach, then, to set up his side in such a way as to leave the team protected.
More serious are the errors he is prone to commit when he is, theoretically at least, in position.
The anticipated Champions League final duel between Marcelo and Mohamed Salah did not really happen, with Salah's injury forcing him off the field early. But while Salah was on the pitch, Marcelo gave away a free kick in a dangerous position when he launched into a foolish "wrong side" challenge on the Liverpool star. And the left-back was also at fault for Liverpool's equaliser. He lost his marking position on Sadio Mane, and played him onside -- while appealing for offside.
Four years ago, when Brazil went down to that extraordinary 7-1 semifinal defeat against Germany, Marcelo was guilty of many similar lapses, constantly unsure of his positioning and running behind the defensive line, playing the Germans onside. His was a disastrous display, and only the fact that some others were even worse shielded him from fierce criticism.
Marcelo, then, is in the fascinating position of going to Russia both as one of Brazil's strong points, and as one of their potential weak points. Opponents will be sure to attack Brazil's left flank, where Neymar is unlikely to drop much to help out with the marking duties.
It could be that Marcelo has been helped by the injury that forces right-back Dani Alves to miss the World Cup. His loss is a blow to Brazil, not least because he is such an important voice in the dressing room, and has some influence on Neymar. He is also a magnificent player, but one with similar virtues and defects to Marcelo. With the pair of them in operation, Brazil can be vulnerable in the space behind both full-backs.
Now that Dani Alves is out of action, coach Tite can ask his replacement -- either Danilo or Fagner -- to play a more conservative role. This would free Marcelo, because it would mean that the more defensive midfielders, Casemiro and Fernandinho, could pay much more attention to plugging the gap on only one side of the field. And Marcelo in a well-balanced side can be much more asset than liability.