Kiekhefer, 27, was designated for assignment on Dec. 3 after being claimed off waivers by the Mariners from St. Louis on Nov. 4. He made 26 relief appearances with St. Louis last season after making his Major League debut with the Cardinals on May 14 at Los Angeles-NL. Over 5 stints with the Cardinals (5/13-6/18, 7/20, 7/26-8/2, 8/3-5 & 8/29-end of season) he held opponents scoreless in 20 of 26 appearances, going 0-0 with a 5.32 ERA (13 ER, 22.0 IP), while walking 7 and striking out 14. The 6-0, 175-pound left-handed reliever limited opponents to a .273 (24x88) average, including a .209 (9x43) average vs. left-handed batters. Kiekhefer also appeared in 29 games with AAA Memphis, going 6-1 with 2 saves and a 2.08 ERA (8 ER, 34.2 IP).
Kiekhefer was originally selected by the Cardinals in the 36th round of the 2010 MLB First-Year Player Draft out of the University of Louisville. Over 7 minor league seasons, he is 20-16 with a 2.65 ERA (110 ER, 373.0 IP) in 264 games, 1 start. He has limited opponents to a .251 (359x1429) average, while walking only 55 and striking out 275. Of his 264 appearances, he has tossed at least 2.0 innings or more in 90 games (34%), including not allowing a run in 59 of those 90 appearances. Kiekhefer has posted a strikeout-to-walk ratio of 5.00 in his minor league career and has issued only 34 walks over his last 286.1 innings dating back to 2012. During this stretch, dating back to 2012, his 5.82 strikeout-to walk ratio (198 K, 34 BB) is tied for the 2nd-highest in the minor leagues, while his 1.07 walks-per-9.0-innings ratio (34 BB, 286.1 IP) is 2nd-lowest in the minor leagues (min. 250.0 IP).