Brawn, who sold the team he rescued from Honda to the German Manufacturer at the end of 2009, departed at the end of Hamilton's first year with the team.
Hamilton, meanwhile, has opened up about his compatriot's departure from the team for the first time.
"I was sad to see him leave because when I joined the team part of the decision process was that he was a part of the team, then obviously he left shortly afterwards, which was not great," he said. "I think what he built over the years is what we are now standing on top of and succeeding upon, so he really helped build a platform, build the foundations and I'm appreciative."
"I loved working with Ross. I grew up watching Formula One with Ross at Ferrari and then the next thing you know I'm in my mum's kitchen having a cup of tea with him, he's come to visit me to talk about joining the team and how he would love for me to drive for them. I felt very honoured that he had wanted me," added the three time world champion.
"Working with him was great, he created a really good atmosphere, very approachable for everyone. I think everyone was really relaxed with him."
Bahrain International Circuit - Winter testing