Ivan Rakitic has rejoined Sevilla from Barcelona after six years at Camp Nou. (More Football News)
The Croatia midfielder has signed a four-year deal with Julen Lopetegui's side.
Barca will receive €1.5million up front for the player, with up to another €9m due in performance-related variables.
New Barca head coach Ronald Koeman is said to have made it clear to Rakitic, who made 42 appearances in all competitions last season, that he would not be in his plans for 2020-21.
Negotiations stepped up on Monday, with Rakitic undergoing a medical after a fee was agreed between the clubs.
Rakitic was a fan favourite at Sevilla and captained them to Europa League glory in 2013-14 before signing for Barcelona.
His first season at the club was a resounding success, the Catalans winning the treble under Luis Enrique, with Rakitic scoring the opening goal in the 3-1 Champions League final win over Juventus.
In total, Rakitic won 13 trophies with Barca, including four LaLiga titles and four Copas del Rey, and he was reportedly the subject of a €90m bid from Paris Saint-Germain in 2018.
However, his position in the first team has come under scrutiny over the past two seasons.
The 32-year-old became the target of criticism from a particular section of the fanbase as results and performances began to dip during the latter part of Ernesto Valverde's time in charge.
Rakitic always maintained he did not want to leave the club despite speculation Barca were keen to offload him, possibly in part-exchange offers for Neymar or Lautaro Martinez, and his frustrations boiled over in April when he told Mundo Deportivo: "I understand the situation but I am not a sack of potatoes to do whatever you want with."
Rakitic's wife Raquel Mauri and her family are from Andalusia and the player has previously admitted he would like to move back to the region and play for Sevilla once his time at Barca came to an end.
In December last year, he told El Desmarque: "If the time was right then we all know that I'd be delighted to pursue this as I've always stated that if I was to return to one of my previous clubs then it would be Sevilla.
"I'm really happy to see the team do so well and they seem to be getting better each year and that's something that greatly pleases me. My dream would be to wear the Sevilla shirt again at some point in the future."