Red Bull motorsport advisor Helmut Marko has warned that the company will drop any driver on its books who is "not delivering".
Red Bull's current driver pairing Daniel Ricciardo and Daniil Kvyat both made the step up from the junior team in 2014 and 2015 respectively, while Toro Rosso's Max Verstappen and Carlos Sainz both impressed in their rookie campaigns last year. Both teams have retained the same line-ups going into 2016 but Red Bull has never shied away from dropping drivers completely if not performing up to expectations.
With several big names on the final year of their contract along the grid there is expected to be some movement in the driver market this year, which could open opportunities elsewhere. Marko says 2016 is not a straight shoot-out between Red Bull's four drivers but makes it clear bad performances will not be tolerated.
"We basically have long-term contracts at the Red Bull junior program and the whole program is based on performance," Marko told F1.com. "So no shoot-out, but be very clear: the one who is not delivering goes."
Marko kept that theme going when asked if its likely teenage sensation Verstappen will be promoted next year, saying: "Let's see what he delivers. The second season is sometimes trickier than the first!"
The Austrian expects Toro Rosso to be ahead of Red Bull in the early races of 2016 despite the fact it has a year-old Ferrari engine.
"They are happy to have this engine rather than none at all. And I could imagine that they will land in front of Red Bull Racing at the start of the season - probably until midseason - because the power difference is still that significant. In midseason probably the performance will drop, as you cannot further develop the 2015 engine."