Boston acquired Miller from the Giants on Monday in exchange for Marcelo Meyer, Jeff Passan of ESPN.com reports.
Miller will make his way to Boston in the midst of the most dominant stretch of his career. Dating back to June 12, the 28-year-old has recorded 14 straight scoreless outings. In 38 appearances this season, the left-hander owns a 2.76 ERA, 1.38 WHIP and 45:22 K:BB through 32.2 innings. With Aroldis Chapman already cemented as Boston's closer, Miller will likely transition into a high-leverage set-up role with his new team.