The Giants claimed Abner off waivers from the Diamondbacks on Wednesday and optioned him to Triple-A Sacramento.
Abner will reclaim a 40-man roster spot with the move to San Francisco, though he'll have to wait a bit before making his debut with the Giants. The 24-year-old lefty reliever made eight appearances with Arizona at the big-league level this season, posting a 6.28 ERA, 1.53 WHIP and 6:8 K:BB over 14.1 innings.