Update: Coach Jeff Fisher confirmed Monday that Jackson did not return to Sunday's game against the Redskins due to a groin issue, the St. Louis Post-Dispatch reports.
Recommendation: In fact, Fisher noted that Jackson could have re-entered the game had Daryl Richardson struggled at all while filling in for him. "There was nothing to it," Fisher said Monday. "His groin was tight. We didn't want to risk further injury. He was OK with it. He understands." In any case, Jackson's groin issue appears to be a minor one, which hopefully will be confirmed once the Rams return to practice this week.