Pierre Gasly says Red Bull is now a "tailor-made" team for Max Verstappen.
Last year, Frenchman Gasly struggled to match Verstappen when he stepped up from the junior team. By year end, he had been replaced by Alex Albon.
Gasly has argued that he didn't get long to prove himself at the top team.
"It could have been much better," he now tells Italy's Autosprint. "If I went back to Red Bull, I would have learned a lot in the meantime.
"At least this season, I'm only interested in racing for Alpha Tauri. All of my energy is into that now. I want to stay in Formula 1 at all costs."
Gasly indicated that it was tough trying to fit in as Verstappen's teammate.
"Yes, that's true. Every driver would like to have a team that is tailor-made, like Red Bull is to him.
"But don't forget that Formula 1 is a team sport," he added. "You can only win if the whole team performs well.
"Everyone needs that help - your performance does not depend solely on yourself and all team members have to give everything for that."