Gerhard Berger feels Toro Rosso made the correct decision to drop Jaime Alguersuari and Sebatsien Buemi as they were "average" at best.
The Faenza squad surprised many pundits by axing both Alguersuari and Buemi and replacing them with Red Bull Junior drivers Daniel Ricciardo and Jean-Eric Vergne.
Berger, though, felt it was time for Toro Rosso to move on as the duo was never going to make the step up to Red Bull.
"I think it's correct, although it is very hard," Berger told a special edition of ORF's Sport am Sonntag.
"For the drivers it is always hard, but for Red Bull and Toro Rosso, it is about preparing drivers - ideally from the Red Bull pool. They need to find one that will eventually be the successor of Mark Webber or Sebastian Vettel when they move on."
He added: "The demands at Red Bull are very high, as we know, and these two [Alguersuari and Buemi] are at the best average."
Red Bull have high hopes for Ricciardo and Vergne and Berger feels the latter has a big future ahead of him.
"I've heard a lot of good things about the young Frenchman - maybe he's a new Sebastian Vettel," he said. "You have to try it, otherwise you do not know."