The Diamondbacks designated Kepler for assignment Sunday.
The veteran outfielder signed with the Diamondbacks in June but has now been dumped from the 28-man and 40-man rosters after posting a .154/.214/.173 slash line in 16 games since the start of August. Kepler, who served an 80-game PED suspension to begin the season, has a .565 OPS with two homers in 145 plate appearances this year.