The team's non-executive chairman believes the Finn is still behind Lewis Hamilton in terms of outright speed but his faculty of adaptation has pleased the F1 legend.
"My first impression is very good," Lauda told Austrian broadcaster ORF.
"He is a Finn so he doesn't talk much, but he works hard to get used to the team. I'm impressed how quickly he could get used to the car."
The relationship between Bottas and his triple world champion team mate is also off to a good start but that could change warns Lauda if the performance gap between the two men closes.
"Now, at the beginning, everything is simple," said Lauda.
"Lewis has everything in his hands and Bottas is getting used to the team.
"Now we wait for the first races to see how they get along, what the gaps are and how everything develops.
"We don't know this yet," he admitted.