Rainey has a 4.74 ERA, 1.42 WHIP and 27:14 K:BB with a win and six holds through 19 innings this season.
The strikeout rate is nice, as is his 97 mph fastball, but there isn't much else in Rainey's numbers to suggest he'll become a reliable part of the Nats' bullpen in the second half. Other than in deep NL-only formats that score holds, the 26-year-old has little fantasy value.