The Catalan side had the Brazilian playmaker in their sights in January, only for the move not to materialise. Naturally, that led to a host of other European clubs being linked with a swoop for the man who is considered one of Brazil's brightest young prospects.
The club's moves for Yerry Mina and Philippe Coutinho meant that Barca had no more wiggle room to add another non-EU player to their squad and thus asked Arthur to ignore offers from elsewhere, on the proviso that Barca revisit the deal as soon as possible.
The transfer window then closed, with Arthur remaining with Gremio and true to their word, Barca looked to accelerate their move.
The next step was agreeing a deal with the Brazilian side in order to avoid paying the player's €50m release clause in full. According to Spanish publication 'SPORT', there is an greement in principle between the two sides ammounting to €40m.
Barca have thus moved ahead of the likes of Chelsea and Manchester United in the queue for Arthur, with the Premier League sharks starting to cirlce after the deal appeared to hit the buffers.
Arthur is thought to have agreed terms with Barca, with the 21-year-old of the opinion that a move to a European heavyweight could add weight to his claim for a place in Brazil's World Cup squad.
Whilst many are assuming the deal is already done, Arthur would be unlikely to pull on a Barca shirt until January 1, 2019, with Gremio not willing to let their star man go until the end of the current Brazilian league season.