Grissom was recalled from Triple-A Gwinnett by Atlanta on Friday.
The 22-year-old is set to take over as Atlanta's everyday shortstop with Orlando Arcia (wrist) landing on the injured list. Grissom has crushed it at Gwinnett this season, slashing .366/.458/.585 with one homer, two stolen bases and a 6:4 BB:K. His glove remains a work in progress, but he showed his fantasy upside last season and should be picked up in most leagues where he's still available.