The 6-foot-6 rookie was signed by the Hawks after failing to get drafted out of Nebraska. The team announced the move Thursday, leaving Atlanta with 17 players heading into the final preseason game.
Petteway played in three preseason games for the Hawks, averaging 1.7 points.
The Hawks must get down to a 15-man roster for Tuesday's opener against Detroit. Lamar Patterson appears likely to claim the final spot over center Earl Barron and forward DeQuan Jones. Patterson was a second-round pick in 2014 who played last season in Turkey.