The Chargers signed Campbell (hamstring) to the practice squad Wednesday, Kris Rhim of ESPN.com reports.
Carolina waived Campbell from injured reserve Friday, but the 23-year-old wideout appears to be past his hamstring issue. He was originally signed by the Chargers as an undrafted free agent in April but was waived at the end of training camp in late August, which led to the Panthers claiming the South Carolina product off waivers.