Alfa Romeo team principal Vasseur will reunite with Bottas for the 2022 season upon his move from Mercedes. Vasseur previously worked with Bottas at his ART Grand Prix squad in both Formula 3 and GP3.
Bottas won the GP3 title in 2011 with ART, putting him on course for an F1 drive with Williams in 2013.
Vasseur felt confident that his prior relationship with Bottas would help lay the foundations for working together again in F1, similar to how he had previously worked with Charles Leclerc before his successful season at Sauber in 2018.
"It's important to have a good personal relationship, full trust, and a good understanding of the other," Vasseur told Motorsport.com.
"I saw it with Charles in the past: when you work together in the junior series, you know the guy for a long, long time. You don't need to speak too much to understand what he is expecting.
"The relationship that you can build in the junior series is completely different to the relationship in F1. We are much more in contact."
Vasseur has said he thinks Bottas will be able to flourish at Alfa Romeo outside of Lewis Hamilton's shadow after the team signed him to serve as its leader on a multi-year contract.
Bottas helped Mercedes to win the constructors' championship in all five of his seasons with the team, and twice finished as runner-up in the drivers' championship, scoring 10 wins in total.
While the Finn struggled to match Hamilton across the course of a season, many of his wins came in dominant displays where he outclassed the rest of the field.
Asked if he had seen signs of such dominance in junior categories, Vasseur replied: "When you want to find positive factors in the junior series, you can always find them.
"But I think your summary was a good one. When everything is perfect, he's able to be flying. He went faster than Lewis in some weekends.
"He did some mega good events on the last part of the season [in 2021]. Also perhaps the fact that we signed and he has a new project, he was a bit more relaxed. I hope that it helped him."
