No, this isn't about Joey Bosa. Believe it or not, the Chargers do have other players on the roster. They've just added a new one, signing C Bruce Johnson after waiving-injured OLB Tyler Marcordes, who was almost certainly going to be on the list of first cuts anyway.
Johnson is an interesting choice of a player to add. He was picked up as an UDFA by the Eagles but was waived earlier this week. That doesn't automatically mean he's not at the required level - Branden Oliver was an UDFA who got waived in the preseason by the Colts in 2014, and their loss has very much been the Chargers gain.
Johnson certainly has some pedigree - he was Maine's starting Center for three years, and in 2015 won the Rimington Award, being recognized as the best Center in the FCS. I'm a big advocate of giving small school players a chance to shine, so this move sits well with me.
Johnson probably won't make the roster (Center is the one position on the OL the Chargers have depth at), but he's got a legitimate shot to make it onto the Practice Squad. For someone available as a Free Agent this late in the offseason, that's a good piece of business by the Chargers. For once.