Daniel Ricciardo had little choice other than to leave Red Bull.
That is the view of Davide Valsecchi, a former GP2 champion who is now a pundit for Italian TV.
He told the Dutch magazine Formule 1 that he thinks Australian Ricciardo decided to join the works Renault team for 2019 because of Max Verstappen.
"Daniel does not want to be the second driver at Red Bull," said Valsecchi.
He said it is "clear" that Verstappen is regarded as the "preferred" Red Bull driver.
"As soon as Verstappen joined Red Bull, you could see his talent immediately, and it's bigger than my friend's," said the Italian, referring to Ricciardo.
"I knew Daniel would do this. Max is just better and I understand why his salary is double or triple that of Dan."
Valsecchi said of Verstappen: "He is extreme in everything. Extremely young, extremely good, extremely confident."