The Chargers placed Colston on the active/non-football illness list Wednesday with an unspecified injury, Aaron Wilson of KPRC 2 Houston reports.
The Chargers haven't offered up a timeline for Colson's return to the field, but he can come off the NFI list at any time during training camp, once cleared to practice. The rookie third-round pick out of Michigan appears in prime position to compete for a starting role at linebacker, assuming he's not sidelined too long.