Zinedine Zidane admits job is on line despite signing contract extension

The Frenchman was slammed in the Spanish media following Wednesday's 2-2 draw with second-tier Numancia even if Real won the last-16 tie 5-2 on aggregate.

It came hot on the heels of a 3-0 loss at home to Barcelona and there was no let up in the criticism after Sunday's 2-2 draw with Celta Vigo in La Liga.

Real Madrid have slipped a remarkable 16 points behind Barcelona in La Liga and occupy the unfamiliar position of fourth in the standings, with their hopes of retaining the title long gone.

Zidane has signed a contract extension until 2020, but appears to be aware that will not save him if the poor run of form continues.

"I just go game to game, year to year," said Zidane.

"It is not easy for the players who play less. We played a good game. We maybe lacked a bit of gas at the end."

A place in next season's Champions League is also far from secure as sixth-placed Villarreal visit the capital on Saturday trailing the faltering Spanish and European champions by only four points.

Anything but three points against Villarreal, who secured a draw at the Bernabeu last season, would pile more pressure on Zidane despite his eight trophies in two years as Real coach.

The coach's declaration on Tuesday that he would not "throw anyone in the mud" has been taken as another sign that he is not strong enough to make the tough decisions his team need.

Zidane's unwillingness to shake things up can be traced to Real's limited activities in the last transfer window.

According to media reports, the club pulled out of a bid to sign French teenage sensation Kylian Mbappe to avoid upsetting Cristiano Ronaldo, Karim Benzema and Gareth Bale, who have only mustered up 10 league goals between them this term.

Mbappe joined Paris Saint-Germain instead and Real weakened their attacking options by relinquishing James Rodriguez and Alvaro Morata, who did not start most games last season but made invaluable contributions from the bench.

The only new arrivals were youngsters Theo Hernandez, Dani Ceballos and Diego Llorente, who have barely featured this season as Zidane's faith in the so-called 'B' team that did so well last season has faded.

So too has Real's form, and unless Zidane can whip his team into shape again, his time in charge could prove to be as short as it was successful.