Gibson was held out of Friday's open scrimmage as a precautionary measure due to groin soreness, Josh Robbins of The Athletic reports.
Gibson's injury doesn't appear to be particularly serious, and he's labeled as day-to-day ahead of Thursday's preseason opener against the Hornets. It's unclear whether he'll be forced to miss any preseason action, but it wouldn't be surprising to see him available for the start of the regular season in late October. During his first year in Washington, the 38-year-old averaged 3.4 points and 1.9 rebounds in 9.8 minutes per game over 49 appearances.