Johnston did not play in the Chargers' 27-7 preseason win over the Texans on Thursday.
Johnston joined Tre' Harris and Ladd McConkey in observing Thursday's exhibition contest from the sidelines while KeAndre Lambert-Smith, JaQuae Jackson and rookie fourth-rounder Brenen Thompson each played 30 or more offensive snaps against Houston. Johnston had his ups and downs in 2025 but finished with a career-high 735 receiving yards across 14 regular-season games, while his eight touchdowns also tied his career best in that category. However, the 2023 first-rounder could be in line for an expanded role in offensive coordinator Mike McDaniel's scheme, especially since Keenan Allen is still a free agent.