Pollack, a former first-round draft pick, suffered a serious neck injury in the second game of the season against the Cleveland Browns in 2006. He played in 16 career games in two seasons and recorded 4½ sacks.
"David has expressed to me that I believe ... he's headed [into] retirement," Lewis said. "He is not completely comfortable medically where he has been given an opportunity ... to play football. We know the quality of person [he is] and he has a bright future no matter what he chooses to do."
Pollack has expressed interest in getting into coaching, Lewis said. Pollack also worked on SEC football broadcasts last season.
James Walker covers the NFL for ESPN.com.