"I've faced a lot of injuries throughout my career and I feel it is in my best interest to hang up the cleats and pursue another career," Dial wrote. "I am excited about what the future holds for my family and I."
The 49ers released Dial on September 2, 2017, and the Packers signed him three days later. He recorded 126 tackles, 4.5 sacks, and four passes defensed through 46 games and 32 starts in four seasons with San Francisco.
Dial registered 19 combined tackles and a pass defensed during his one season with Green Bay, where he appeared in 13 games with two starts.
Dial has not played since the 2017 season.