Tuesday, they made it official.
The right-handed relief pitcher has reportedly been suffering from forearm tightness in the most recent part of a season that has also been fairly wayward otherwise. In 13 appearances for the Diamondbacks this season, Putz, 37, has compiled a 5.40 ERA, thanks in part to a strikeout-to-walk ratio that is lower than it has been since 2005, at 2.00.
The Diamondbacks' corresponding move will be the recall of 24-year-old Evan Marshall, who has allowed just one earned run in 14 appearances (16.2 innings pitched) for Triple-A Reno in 2014.
Marshall was a fourth-round pick of the Diamondbacks in 2011.
According to Baseball America, Marshall's fastball ranges between 92 and 96 mph and carries heavy sink. The publication also states that the prospect has "enough stuff to pitch at the back of the bullpen," thanks to a curveball that they describe as "hard" and "true" and a delivery deemed "funky".
Marshall boasts a 10.3 strikeouts-per-nine rate this season at Reno.