He's thrown 35 consecutive scoreless innings between Double-A Frisco and Round Rock and is 3-0 overall with a 0.52 ERA in 33 outings. Since his June 25 promotion to Round Rock, Klein has tossed 18 1/3 scoreless innings while racking up 28 strikeouts -- good for an average of 13.7 strikeouts per nine innings.
A 30th-round selection in the 2011 First-Year Player Draft, Klein has breezed through the opposition to this point in his career. Since making his professional debut in 2011, Klein has tallied a 16-3 record to go along with a 1.87 ERA over 121 appearances, all but two of which have come out of the bullpen.
As for Feierabend, the southpaw posted a 6.14 ERA over six appearances (7 1/3 innings) with the Rangers after his July 12 promotion.
Paul Casella is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.