Bears' Robert Quinn: Nursing lower back issue

Quinn didn't practice at mandatory minicamp Tuesday due to a lower back injury, Jeff Dickerson of ESPN.com reports.

Coach Matt Nagy said the team is exercising caution, so Quinn's availability for the start of training camp shouldn't be in question. The 31-year-old struggled during his first season in Chicago with 20 tackles (14 solo), a career-low two sacks and three forced fumbles in 15 games.