Rodriguez was added to the Giants' major-league roster Wednesday, Andrew Baggarly of The Athletic reports.
Manager Gabe Kapler said Wednesday that Rodriguez's velocity increased in recent throwing sessions while serving on the taxi squad, and he'll join the pitching staff along with right-hander Trevor Cahill. Cahill is scheduled to start Wednesday but is reportedly only built up to approximately 50 pitches. Rodriguez could serve as a long reliever if Cahill isn't able to last very long against the Astros. Rodriguez made 28 appearances (16 starts) for San Francisco last season, posting a 5.64 ERA and 71:36 K:BB over 99 innings.