The 32-year-old's contract with the Camp Nou giants expired at the end of July, but sporting director Deco was supposedly keen to keep Roberto at the club for a little while longer.
The versatile Spaniard, who functioned as both a right-back and central midfielder for Barcelona, supposedly accepted the club's renewal offer, but they could not register him until the middle of August.
Furthermore, Roberto was further down the list than other players when it came to registrations, and as the 32-year-old did not want to wait around, he ultimately chose to clear out his Camp Nou locker.
Roberto's departure ended a glittering 14-year career as a senior Barcelona player, during which he provided 19 goals and 43 assists in 373 games while winning a staggering 22 major trophies.
Roberto to snub La Liga trio for Premier League move?
According to Mundo Deportivo, the Spain international has offers to continue in La Liga, with all of Valencia, Girona and Sevilla prepared to battle for his signature in the coming weeks.
However, as Roberto has spent the entirety of his career in his homeland, he is supposedly keen to test himself in a different country and is instead pursuing a move to the Premier League.
The report adds that the former Barcelona man is currently evaluating an offer from an unnamed party, and his future could even be resolved in the next few days.
It is unclear which Premier League club is pursuing the signature of Roberto, who served as Barcelona's captain during his farewell campaign and was seen as an invaluable member of the dressing room.
Which Premier League clubs could sign Roberto?
Whether Roberto is working on a move to a Big Six side or a team lower down the Premier League pecking order is unclear, but if he joins one of the former clubs, one outfit immediately springs to mind.
Manchester United are at risk of seeing their right-back and midfield department thinned this summer, as Aaron Wan-Bissaka is being heavily linked with an exit five years on from his arrival from Crystal Palace.
Furthermore, all of Casemiro, Christian Eriksen and Scott McTominay could depart before the transfer deadline, and Roberto would provide an experienced option at both right-back and in the heart of midfield.
Arsenal and Liverpool could both do with reinforcements in the number six role too, but the Gunners and the Reds are likely to target younger reinforcements than the 32-year-old Roberto.
However, the Spaniard could prove a useful ally to the teenage Kobbie Mainoo at Man United, although his Pep Guardiola connections means that Manchester City - who could lose Joao Cancelo and Kalvin Phillips this summer - cannot be disregarded either.