Christiansen (undisclosed) was placed on Chargers' practice squad COVID-19 list Friday, Daniel Popper of The Athletic reports.
Christiansen has appeared in two games for the Chargers this season -- in Week 6 against the Ravens and in Week 10 against Minnesota -- playing a total of 40 special-teams snaps and recording one solo tackle. He'll try to clear protocols quickly and try to earn another shot on the active roster.