Real Madrid have sacked Julen Lopetegui as manager after four and a half months in charge at the Bernabeu.
Real, Champions League winners for the past three years, are ninth in La Liga after their worst start since 2001-02.
The 52-year-old will be "provisionally replaced" by ex-player Santiago Solari, coach of B team Castilla.
Lopetegui took a training session on Monday but his fate was confirmed following a board meeting.
A club statement said "there is a great disproportion between the quality of the staff of Real Madrid" and "the results obtained to date".
Eight of the current Real squad are on the 30-man shortlist for the 2018 Ballon d'Or.
Solari has a favourable run of fixtures for the start of his tenure, beginning with a Spanish Cup match against Segunda Division B Group 4 side Melilla on Wednesday.
Real then play Valladolid - sixth in La Liga - on Saturday, Group G's bottom side Viktoria Plzen in the Champions League on 7 November, and the mid-table Celta Vigo the following Sunday.
It is the second time Lopetegui has been sacked this year having been dismissed by Spain two days before the World Cup.
That sacking came after it emerged the Spanish football federation was unaware he was in talks to take the Real job after the tournament.
Real have 14 out of a possible 30 points in the league this season and have taken only one from their past five matches - their worst run since they went pointless in the final five games of 2008-09 under Juande Ramos.
They are now six points above the Spanish top flight's relegation places, and seven behind leaders Barcelona.
|Real problems in Madrid|
|Lost four and drawn one of their past five games|
|Seven points behind La Liga leaders Barcelona after El Clasico - with a goal difference of zero|
|Lost at CSKA Moscow in Champions League, and narrowly beat struggling Viktoria Plzen|
Who next in the Real hotseat?
The favourite to replace Lopetegui in recent weeks had been former Chelsea boss Antonio Conte, who has been out of management since being dismissed by the Blues in July after finishing fifth last season.
But negotiations with the Italian are reported to have stalled and 42-year-old Solari has been given an opportunity, mirroring the appointment of former boss Zidane, another popular ex-player who had been in charge of Castilla.
Zidane took charge after Rafael Benitez was sacked in January 2016 and the Frenchman guided Real to three successive Champions League titles, before stepping down in May.
Former Real and Argentina midfielder Solari replaced Zidane as coach of Castilla, who are fifth in Segunda Division B, three points behind leaders Ponferradina.
Under Spanish regulations, an interim coach can be at the helm for a fortnight - but must be appointed officially after 15 days, or not at all.
Manchester United manager Jose Mourinho - who won La Liga and the Copa del Rey during his three years at Real from 2010-13 - and former Everton boss Roberto Martinez, who led Belgium to the World Cup semi-finals, have also been linked with the post.
Spanish football expert Guillem Balague on BBC Radio 5 live
"Antonio Conte is asking for so much. He is asking for two and a half years, asking to be a manager, asking for more money than Real Madrid are willing to pay. They are surprised this has not gone smoother. On Sunday, they were very optimistic Conte would replace Lopetegui.
"Florentino Perez always asks the leaders of the dressing room about managerial decisions. When he got rid of Rafael Benitez, he asked Cristiano Ronaldo and Sergio Ramos. He has asked Sergio Ramos this time and he doesn't like the idea of Conte.
"Fans will be underwhelmed for sure. Solari hasn't impressed in the league, but what the fans don't realise is every year he has been given a bunch of kids in the third tier, which is all about adults and being strong mentally and physically - and his players have not been.
"But about 12 players from his team in the past two seasons now play in the first or second divisions. That means he is a good coach.
"There is a lot of hope for him, but everyone feels it is a little bit too early - even the board."