Anderson (back) wasn't spotted on the field during Thursday's practice, Josh Weinfuss of ESPN.com reports.
With consecutive absences from practice to begin Week 18 prep, Anderson doesn't appear to be in a good spot as Sunday's game in San Francisco approaches. Unless Anderson can fit in some on-field activity Friday, he could be ruled out upon the release of the Cardinals' final Week 18 injury report. If Anderson is sidelined for the season finale, a few extra snaps could be opened up for A.J. Green and/or Andre Baccellia.