Thompson (undisclosed) was on the field for Sunday's training camp practice, Kris Rhim of ESPN.com reports.
Thompson was sporting a non-contact jersey during Sunday's session, but it's a positive sign after he was held out of Saturday's practice due to an unspecified injury. The rookie fourth-rounder is battling for a rotational spot in the Chargers' offense, and he'll look to make his case for regular playing time in Thursday's preseason finale against the Rams. Thompson has caught three passes on eight targets for 39 yards through two preseason games, adding one punt return for 12 yards.