Solari was handed a contract until 2021 appointed only five months ago might not last the season if Ajax beats madrid reaches the quarters.
Madrid: Santiago Solari's future is likely to hinge on Real Madrid again winning the Champions League but two defeats by Barcelona in four days have brought old problems back to the surface.
After being knocked out of the Copa del Rey and effectively deemed irrelevant in the title race, a third loss in as many games could see Madrid's season wiped out in a week.
"We have to react," said defender Dani Carvajal.
"It's probably been one of the toughest weeks in my time here."
Ajax deserved more from the 2-1 loss in Amsterdam that, in theory, puts their opponents firmly in charge ahead of the second leg on Tuesday.
But three consecutive defeats at the Santiago Bernabeu for the first time in 15 years means Madrid will be feeling the heat.
Solari too, the coach that was handed a contract until 2021 when appointed only five months ago but who might not last the season should Ajax do the unthinkable and reach the quarter-finals.
Jose Mourinho's criticism as a pundit for bEIN Sports on the latest Clasico will be seen as opportunistic but the reality is he is still well-regarded at Real. Unlike other potential successors, he is also available to start immediately.
Still, Solari will know Madrid have been here before.
Last season, Zinedine Zidane's team crashed out earlier in the Copa del Rey and to Leganes, not Barcelona. They were adrift in La Liga too.
But victories in Europe over Paris Saint-Germain and Juventus blurred those failures while beating Liverpool in the final seemed to extinguish them almost completely.
Solari will surely pay the price if domestic disappointment is extended into the Champions League, where context could be significant - the stage, opponent and manner of defeat - but after four triumphs in five years, it is hard to imagine anything less than lifting the trophy would be deemed a success.
For Solari, that is a high bar set, and a reminder perhaps of why Madrid found so few elite coaches eager to follow Zidane last summer.
Grim Goal Record
Real had finished 17 points behind Barcelona and then sold their best player. In the years with Cristiano Ronaldo, Madrid's goals scored tally at this stage in the league was 71, 62, 85, 64, 73, 75, 71, 67, and 62. This season it is 43.
And against Barcelona, the difference was precision in the final third, where Barca boasted Lionel Messi, Luis Suarez and Ousmane Dembele while Madrid had an out-of-form Gareth Bale, an inexperienced Vinicius Junior and Karim Benzema, who only scored five league goals last term.
Under Julen Lopetegui in October, Madrid went almost eight hours without scoring and the reaction to the latest defeat sounded familiar.
"We failed to finish, just like the other day," said Solari. "When that happens, you cannot win the game. When you lack goals, you struggle," said Ramos.
Solari certainly shoulders some of the blame for Bale's dip, having consistently relegated him to the bench in recent weeks while offering only meek support in the face of heavy criticism in the Spanish press. "He tried, like the rest of the players," Solari said on Saturday.
He could also perhaps do with the creativity of Isco, who came on as Madrid sought an equaliser against Barca but is unlikely to feel much loyalty to his coach, having not started a single league game during his tenure.
The question is whether Solari can now revive his marquee players and cojole the youngsters, many of whom have been the driving force of his team in recent months. In the Champions League, the pressure is on to deliver.
"We need the league for fitness and rhythm," said Ramos.
"So we must continue working and keep winning games. We have another final in the Champions League on Tuesday and we will fight for it." he added.