Johnson (knee) underwent knee surgery Tuesday, Michael Gehlken of the San Diego Union-Tribune reports.

EDGE Analysis

As is normally reported in such cases, the procedure was said to have gone well, though at this point there is still no timetable for the wideout's potential return to action. Even if Johnson's knee repairs Tuesday were minor, time seems to be working against him relative to the possibility of suiting up in Week 1. In his absence, Keenan Allen and Travis Benjamin top the Chargers' wideout depth cart, while Tyrell Williams, Dontrelle Inman, James Jones and Javontee Herndon jostle for slotting behind the team's top duo.