Quique Setien was named Barcelona coach late on Monday, tasked with the job of restoring the club's iconic passing style, but the appointment represents a huge gamble for the Catalans given the 61-year-old's lack of success at the highest level.
Koeman, who scored the winning goal for Barça against Sampdoria in the 1992 European Cup final, has made no secret of his desire to return to the club and has a clause in his contract allowing him to leave for Barcelona after this summer's European Championship.
He won a league title in his second season as manager.
"Quique Setien will be the new FC Barcelona coach".
An announcement was expected all day, but a delay in finalising the termination of Valverde's contract temporarily held things up.
He will also have to do without Luis Suarez, who will be missing for the next four months after having surgery on his right knee.
The former Liverpool star has been impressive this season for Barcelona scoring 14 goals in 23 games for the Catalan giants.
They return to action on Sunday against Granada and it remains to be seen who will be in the Nou Camp home dugout. Barcelona play Napoli in the last 16 of the Champions League next month and Real Madrid in the league at the start of March.
As for Valverde's replacement seems to be a surprise to say the least.
The recent elimination from the Spanish Super Cup after their defeat against Atletico Madrid has reignited a long due concern of millions of Barcelona fans, the sacking of Ernesto Valverde.
The former Athletic Bilbao coach's position has been described as untenable, with president Josep Maria Bartomeu and directors Javier Bordas, Oscar Grau and Eric Abidal locked in discussions late on Sunday night.
A delegation is understood to have met with the club's record appearance holder in Doha last week, although Barcelona were reluctant to reveal the true nature of the discussions. "Both of them have been at Barca and know the club".
"The final decision is in the hands of Al-Sadd's management, in the hands of the manager and the hands of Barcelona's management".
Increasingly, though, Valverde's achievements faded from view and his failures began to overshadow them.
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