The Dons face all three of League One's relegated sides inside their first eight matches, with Chesterfield up first on the opening day.
Brown's assistant Stuart Cash spent two seasons with the Spireites as a player, adding some personal interest to the clash.
"Apart from being Stuart's old club, they are one of the favourites for promotion," Brown told the club's official website.
"They have invested a lot of money in trying to bounce back so it is going to be a difficult one for us.
"We will need to get some points in August because September is going to be hard for us as we face a few more of the teams who are likely to be challenging for promotion at the end of the season."M