Red Bull's Helmut Marko says Daniel Ricciardo and Max Verstappen are on equal footing although he rates the latter's performance as superior in 2017.
Ricciardo finished fifth and just ahead of his team mate in the championship, but the Dutchman's trumped the Aussie in terms of race wins, 2 to 1.
Verstappen was recently awarded a lavish new three-year contract with Red Bull Racing while Ricciardo remains on the sidelines with regard to his future, leading pundits to believe the 20-year-old is now the team's de facto number one driver.
"I didn’t favour [Max], but in qualifying he was most of the time faster," explains Marko.
"With seven DNFs his season was not a walk in the park and sometimes his morale was really down, but it was a steep learning process for him and he came out better than he was before. His two wins were the proof.
"We don’t have a number one. Both drivers are equally treated and it is up to them to define the pecking order. I will always love the faster one!"
Red Bull was once again slow to pick up the pace this year, with aerodynamic correlation issues dogging the Milton Keynes-based outfit in the early part of the season.
As it corrected its trajectory, engine reliability issues then came to the fore, but ultimately Marko believes both drivers made progress over the course of the year as they pushed each other.
"Ricciardo struggled a bit in the first half of the year but then adapted and on some occasions was at the same speed - and sometimes even faster - than Max.
"My verdict is both drivers developed from last season. They pushed each other to the next level and hopefully next year to the very top!
"On the circumstances - or let's say luck - we had more than ten DNF's. Picture this! This outstanding record speaks for itself.
"Without that we would have been significantly further up in both championships - P2 would very likely have been ours."