Douglas played in five preseason games with the Pacers and averaged 6.6 points and 1.6 assists.
He signed as a free agent in August after spending last season in New Orleans. The 6-foot-2 guard also had played with New York, Houston, Miami, Golden State and Sacramento. He averaged 7.6 points, 2.2 rebounds and 2.2 assists in his first six NBA seasons.
Petteway, the 6-foot-6 former Nebraska star, was signed Sunday.
Indiana opens the season Tuesday at Toronto.