Los Blancos chiefs have reportedly been weighing up whether to part company with Zidane at the end of the season following a disappointing 2017-18 to date.
Out of the Copa del Rey and La Liga title race, Madrid are now left fighting for silverware on just one front - the Champions League, which they have won in successive campaigns under their current boss.
Zidane also brought the Spanish title to the Bernabeu in his first full campaign following a four-year absence, while winning two UEFA Super Cups, two Club World Cups and the Spanish Supercopa during his time at the helm.
Kroos has therefore brushed aside the criticism aimed at his manager in recent weeks, telling Marca: "In a team like Real Madrid, arguments always arise when things are not going well.
"Zidane has won eight titles in two years, that's more than enough. We have gone through a difficult phase, but in recent weeks we have raised our level and I am confident that we will be very successful going forward.
"This victory is very important because the Champions League is the only competition we can win right now. Although I didn't feel all of the pressure was on us because we won the last two. We are Real Madrid, so it's always there."
Madrid beat Paris Saint-Germain 3-1 in the first leg of their Champions League last-16 tie earlier this week.