Max Verstappen says he is still getting on well with his rookie teammate.
The young Toro Rosso duo, whose combined age is an amazing 37, have been making their mark on formula one so far in 2015.
Spaniard Carlos Sainz, 20, knows what the target is.
At the weekend, he demonstrated a Red Bull F1 car in Peru, telling EFE news agency he would be "very happy" to race for the premier team for real one day.
"I hope I get the chance," said Sainz.
Also hoping the very same thing, however, is Verstappen, although the 17-year-old Dutchman says his relationship with Sainz is not suffering yet.
"We help each other, we talk a lot, we don’t hide information from each other as happens in other teams," Verstappen told the Spanish daily El Pais.
Told, however, that Red Bull is likely to choose between them for the next Red Bull promotion, he added: "I hope that does not affect things, because at the moment we are both working (together) really well."