Speaking on his podcast, Einfach mal Luppen, the former Real Madrid midfielder voiced his support for his ex-teammate as Ronaldo remains locked in a dispute with the Saudi Pro League over alleged financial discrepancies.
"The best player I played with was Cristiano Ronaldo," said Kroos.
"Cristiano scored more goals than the games he played at Real Madrid."
He added: "The Saudi league is a strange phenomenon. No one had heard of them before the arrival of Cristiano Ronaldo, and now they disrespect the man who put them on the world map.
"If Cristiano leaves tomorrow, this league will lose all its charm. Without Ronaldo, no one would see the Saudi league."
The remarks have also served as a reminder of Kroos' enduring influence, even after his departure from Real Madrid. His exit is increasingly regarded as a major turning point in the club's history, with issues compounding month by month since he left.
A legendary figure at the Bernabeu, Kroos was not only pivotal on the pitch but also an authoritative presence off it, helping to keep standards high and emotions in check.
Real Madrid have struggled to cope without him. The loss of Kroos has weakened control in midfield, with the team often lacking rhythm and composure. His influence in the dressing room is also sorely missed, leaving a leadership vacuum that has yet to be convincingly filled.
The club's objective is now to find a "new Kroos" by June, a task that underlines the scale of the challenge facing Madrid's recruitment strategy.
Real Madrid maintained their flawless start to 2026 in La Liga after grinding out a 2-0 victory over Valencia at Mestalla, with Alvaro Carreras and Kylian Mbappe striking to keep the title race firmly alive.
Real Madrid remain just a point behind Barcelona in the race for the LaLiga title after both sides won at the weekend.
Real Madrid face a crucial La Liga test at Valencia on Sunday, as they look to keep pace with leaders FC Barcelona.
Real Madrid's new era under Alvaro Arbeloa has quickly revealed a clear pattern - a trusted core of players carrying the team through the early weeks of his reign.
