Knox injured his lower left leg during Tuesday's practice, Alaina Getzenberg of ESPN.com reports.
As the Bills kicked off mandatory minicamp Tuesday, safety Taylor Rapp broke up a Josh Allen pass directed at Knox, who then took a hit from a late-breaking Kaiir Elam. Knox was tended to by the team's training staff, took some time to get to his feet and didn't rejoin his teammates for on-field work. With two more minicamp sessions to go this week, it wouldn't surprise if Buffalo takes a cautious approach with Knox to ensure he's as healthy as possible for the start of training camp in late July.