Half of Red Bull's Formula 1 driver lineups for 2020 remain uncertain.

Max Verstappen is certainly leading the top team, while the energy drink company announced on Wednesday that Pierre Gasly is definitely staying at Alpha Tauri next year.

The identity of Gasly's teammate is not clear, however.

Daniil Kvyat looks likely to lose the seat, but whether it goes to Japanese rookie Yuki Tsunoda or Alex Albon is yet to be decided.

Tsunoda denies that the departure of his backer Honda will make a difference.

"No, the situation for me has not changed at all because of Honda," he told as-web.jp. "Helmut Marko would never have included me in the Red Bull program otherwise."

Tsunoda, however, is confident: "I'm not the fastest driver in the world yet because of Max Verstappen. But in the end I want to overtake him and be the best."

If the struggling Albon is dropped by Red Bull Racing, Tsunoda's chances may dwindle as the outfit gives the British-born Thai driver a 2021 lifeline.

Former Red Bull driver Robert Doornbos thinks Albon will definitely be dropped.

"He won't sleep well for the next few days," he told Ziggo Sport. "In Imola he has to strike back to have even a small chance of that seat, but I don't see it happening."

The candidates to replace Albon are Nico Hulkenberg and Sergio Perez.

"Nico is quick, smart and always says what he thinks, unlike most of the other drivers who just parrot what the teams tell them to say," former F1 supremo Bernie Ecclestone told Sport1.

"Red Bull should take him (Hulkenberg) because his character also suits them. More importantly, he can deliver results because he is very strong in the head - you have to be if you're next to Max Verstappen, who is a real force of nature," he added.

Dutch sources believe Sergio Perez is the favourite, thanks to his powerful Mexican backers and Red Bull's desire to crack the Mexican market with its energy drink.

However, Dr Helmut Marko said: "We already have a business relationship with the Mexicans, regardless of Formula 1.

"It is a purely sporting decision," he insisted.