Amateur career Kiekhefer attended
Oldham County High School in
Buckner, Kentucky. The
Cleveland Indians selected him in the 37th round of the
2007 Major League Baseball draft. He did not sign with the Indians and played
college baseball at the
University of Louisville. In 2009, he played
collegiate summer baseball with the
Wareham Gatemen of the
Cape Cod Baseball League.
St. Louis Cardinals in The
St. Louis Cardinals selected Kiekhefer in the 36th round of the
2010 Major League Baseball draft and he signed After signing, Kiekhefer was assigned to the
Johnson City Cardinals, and after one game, was promoted to the
Quad Cities River Bandits where he finished the season with a 5.14
ERA in 28 innings pitched out of the bullpen. In 2011, he returned to Quad Cities where he pitched to a 4–1 record and 1.26 ERA in 57 relief innings, and in 2012 he played for the
Palm Beach Cardinals where he was 2–2 with a 2.24 ERA in 46 relief appearances. He spent 2013 with Palm Beach and the
Springfield Cardinals where he was a combined 4–5 with a 3.43 ERA in 36 games between both teams, 2014 with Springfield and the
Memphis Redbirds where he posted a combined 2–5 record and 2.90 ERA in 55 relief appearances, and 2015 with Memphis where he was 2–1 with a 2.41 ERA in 50 games. The Cardinals added him to their
40-man roster after the 2015 season. He began 2016 with Memphis. The Cardinals called Kiekhefer up to the major league roster on May 13,
2016. The following day, he made his major league debut in
Los Angeles in the sixth inning against the
Dodgers, allowing no walks and striking out four in innings. The only hit and run charged to him—both firsts of his career—was a home run to
Corey Seager. He was optioned to Memphis and recalled to St. Louis multiple times during the season before being recalled for the remainder of the season on August 29. In 29 appearances for Memphis he was 6–1 with a 2.08 ERA, and in 22 innings pitched for St. Louis he compiled a 5.32 ERA.
Seattle Mariners Kiekhefer was claimed off waivers by the
Seattle Mariners on November 4, 2016. On December 9, Kiekhefer was removed from the 40-man roster and sent outright to the Triple-A
Tacoma Rainiers. He spent all of 2017 with Triple–A Tacoma, where he pitched to a 3–3 record with a 4.47 ERA, 42 strikeouts, and three saves in 49 games. Kiekhefer elected free agency following the season on November 6, 2017.
Cincinnati Reds On February 17, 2018, Kiekhefer signed a minor league contract with the
Cincinnati Reds. In eight appearances for the Double-A
Pensacola Blue Wahoos, recording a 1.13 ERA with 10 strikeouts over eight innings of work. Kiekhefer was released by the Reds organization on April 30.
Oakland Athletics On May 2, 2018, Kiekhefer signed a minor league contract with the
Oakland Athletics. He began the season with the Double–A
Midland RockHounds before being promoted to the Triple–A
Nashville Sounds. He was promoted to the major leagues on September 1. Kiekhefer elected free agency on October 15. On October 18, 2018, Kiekhefer re–signed with the Athletics organization on a minor league contract. In six appearances split between Las Vegas and the rookie–level
Arizona League Athletics, he struggled to a 12.79 ERA with 6 strikeouts across innings pitched. Kiekhefer elected free agency following the season on November 4, 2019. ==Post-playing career==