While Quique Setién has toyed with the idea of reverting to a back three, which might be his true preference, it seems he has recognized that Barcelona can’t or won’t adapt to it. Instead we shall probably see a back four, and perhaps, a 4-3-1-2. That’s the formation the team used against Villarreal to devastating effect, with Lionel Messi as a playmaker and Antoine Griezmann and Luis Suárez deployed as forwards.
The issue is that Barcelona lack bench options, and it’s doubly so when you consider this particular game. The team was already short on players, but it’s worse for this game: Martin Braithwaite is ineligble for the Champions League, while Sergio Busquets and Arturo Vidal are out through suspension.
Samuel Umtiti is injured. Ousmane Dembélé is still racing for fitness and unlikely to make it. Clément Lenglet, Antoine Griezmann, and Ronald Araújo (who is coming from the B team) are recovering but considered fit enough to play.
It’s worse when you consider five substitutions are allowed. Barcelona may not have enough players to make them all.
Marc-André ter Stegen, Sergi Roberto, Gerard Piqué, Lenglet, Jordi Alba, Frenkie de Jong, Ivan Rakitić, Suárez, and Messi are all practically guaranteed to start.
Nélson Semedo seems extremely likely to start, too. That makes ten, and one open spot in the XI - which will probably either be Riqui Puig or Antoine Griezmann.
We can assume that whoever misses out will join from the bench, as will, almost certainly, Ansu Fati. That would make up the starting XI plus two subs. Junior Firpo would likely be the third sub Setién would use, but after that?
There’s still two subs to use. Ronald Araújo could come in, but he’s coming back from injury and it would be unusual to throw in another centerback, particularly one as young as him, in a game of this magnitude. I suppose Monchu could get a run out. This would be his senior team debut though. To be fair, he is Barcelona B’s captain and very highly rated at the moment. Konrad de la Fuente has also trained with the first team, but to give a 19-year-old his senior team debut in a tricky match like this seems highly unorthodox. The same could be said of a glut of B team players training with the first team: Ludovit Reis, Óscar Mingueza, and Jandro Orellana.
Overall energy levels could be a problem for Setién if he only uses two, three, or four subs while Napoli uses five. His theory of wearing down the opposition through making them chase the ball wouldn’t really work.
There have been reports that Setién tried to get his team to use a three-man line but it didn’t quite work. It seems the three-man line is his preference, but it is not his squad’s. The fact he tried again, and perhaps it failed again, only underscores it.
With 4-3-1-2, Barcelona give maximum freedom to their attackers, but they do lose quite a bit of width. The fullbacks will have to push up quite high to give the team width, exposing Barcelona to counters - which is how Napoli got a goal in the first leg.
Barcelona will need their best “lock-pickers” to find spaces in Napoli’s defense. Sergio Busquets provided the defense splitting pass that lead to Griezmann’s goal in Italy. He won’t be available, so players such as De Jong, Puig, and of course, Messi himself will be looking to play those throughballs and lobbed passes to get in behind a massed defense.
Lorenzo Insigne is a doubt for Napoli, and it’s a crucial one. He’s one of their main stars and if he’s not fit, or plays but isn’t fully fit, that could be a complicating factor for the Italians for sure. Napoli would usually look for him when starting a break as he has pace and can hold up the ball. They’ll be happy to have Dries Mertens back from injury. He exited the first leg prematurely, and was a doubt for the second leg initially. He scored in the first leg and is always a threat.
With a 4-3-3 formation that morphs into 4-5-1 when defending, Napoli will try to amass bodies in the center of the pitch. The wings will be left relatively open, but if all Barcelona can do when they receive on the flanks is pass back to the middle, it will be sterile possession. A couple of things could help the Catalans here though.
First, the pitch. The Camp Nou will be wider and more familiar, and will slightly decongest the middle. Second, Jordi Alba. He’s not the player he used to be, but he offers more going forward than Firpo, who started the away leg. Perhaps Firpo has improved since then, but that game, he felt very nervous and made an error leading to goal, and offered little in attack.
Third of all, Arturo Vidal was deployed as a winger in the first leg. Having the ability to use Griezmann as a forward, or perhaps Fati, will be an upgrade. I suspect Fati will improve the wing play for this team more than the Frenchman.
Fati will be a crucial player, probably off the bench. He can beat people one on one, which is exactly the kind of threat Barcelona need to help get more space in the middle. My worry is that with a 4-3-1-2, Barcelona will pack the middle even further, and leave the wings completely once again.
Another key for Barcelona will be the press. Napoli were actually quite brave about playing risky passes once they recovered the ball in the defensive zone, hoping to formulate a deadly attack on the counter rather than smashing it upfield. This is when Barcelona have to press them into mistakes, hoping to steal the ball and score quickly with the opponents not fully set.
This will be a tough game for both teams, although betting markets have Barcelona as a reasonable favorite. Playing at home, and with an away goal, you’d expect Barcelona to go through, but this will be a very tight contest in any case.