For all their lever pulling and financial shenanigans this summer, Barcelona's otherwise-impressive squad still has one glaring issue that needs to be resolved over the next 12 months: how to replace Sergio Busquets as the 34-year-old's time at the top begins to wind down.
A potential long-term solution, though, might not be far away.
Andrey Santos has already been compared to Busquets in his native Brazil, and reports suggest that Barca have already seen two bids for the teenage midfielder rejected by Vasco da Gama. Paris Saint-Germain, Manchester City, Newcastle and Everton have also been linked with the 18-year-old.
The comparison to Busquets is fair enough in terms of his passing ability and the way in which Andrey is able to tackle, be press resistant and screen the defence, though it is the extra dimension he can bring in the final third that makes him one of the most intriguing defensive midfield prospects in the world.
He possesses the stamina to play a true box-to-box role, can carry the ball length of the pitch, and his debut season as a first-team regular has also illustrated Andrey's ability to chip in with a decent amount of goals, both from open play or getting on the end set-pieces.
Some, then, see him more as a No.8, which is the jersey he wears at Vasco, following in the footsteps of one of the club's eternal icons: Juninho Pernambucano.
“Physically, he is a monster," Juninho, who made his name in Europe thanks for his free-kick ability while at Lyon, said of Andrey when talking to the Resenha Loading YouTube channel. "Without the ball, his participation in the game is total. I wanted to see his GPS, because he doesn't stop! And technically, he's way above the others.
"He's not going to be better than me, he's going to be much better than me. He is a much more complete player. At 18, I didn't play half as much as he does, I'm not ashamed to say that."
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As well as Juninho, Andrey has also surpassed recent Vasco academy graduates Philippe Coutinho, Douglas Luiz and Allan - all of whom now play in the Premier League - in terms of what he has achieved at such an age.
The youngest goalscorer in the club's history, he has netted five times in his 25 first-team appearances, and though the bulk of them have come in Serie B, there is little doubt that he would be able to have a similar impact were he to be playing in the top flight.
"It doesn't even seem like he's this young," Vasco's veteran midfielder, Nene, said in a recent interview. "He has an incredible maturity in training, it seems like he has been with us for many years.
“He has a vision of the game, a lot of quality and likes to break lines. He is already in the Brazil Under-20s team and who knows, maybe soon he will be shining in the senior national team?. He will be a great player.”
Andrey has gone on quite the journey to reach such a level, with his footballing education having begun at the age of four when he was an overweight toddler who was enrolled into a local futsal club in Rio de Janeiro by his grandmother.
She was concerned by Andrey's size, but he soon fell in love with the game and shed his baby fat before catching the eye of Vasco's scouts two years later.
Having gone on to become the club's youngest debutant in the 21st century, now Vasco are working hard to tie him down to a new contract so as to keep him at the club for at least another 12 months.
They know that the lure of Europe will eventually be too much for Andrey to resist, but Vasco are keen to ensure they get a fair price, with sums of around €35 million (£30m/$35m) having already been mooted for a player who is keen to keep his feet on the ground.
“I'm very focused, serious, and with a winner's mentality," Andrey told ge. "I want to win all the time, and I don't let my team-mates rest, because I always want to evolve."
That evolution could yet carry him to Camp Nou. A more dynamic version of Busquets could find himself starring for Barcelona.