Kelly signed as a free agent with the Atlanta Braves in November 2013.[6] He was promoted to the major leagues on June 28, 2015.[1][7] He made his major league debut on June 30 against the Washington Nationals, pitching one inning, in which he gave up one run on two hits, while recording a strikeout and a walk.[8] He was released on March 5, 2016.[9]
On July 15, 2016, Kelly signed with the Vaqueros Laguna of the Mexican League. In 14 games for Laguna, he recorded a 4.38 ERA with 10 strikeouts across 12+1⁄3 innings pitched. Kelly was released by the Vaqueros on August 11.[11]
On May 17, 2017, Kelly signed a minor league contract with the Seattle Mariners. He pitched in relief for the Triple–A Tacoma Rainiers & Double–A Arkansas Travelers, finishing the season with 2.97 ERA, 32 strikeouts in 30+1⁄3 innings, and an .86 WHIP with 6 saves.[13] He elected free agency following the season on November 6.[14]
Kelly continued putting up good numbers in 2017 when he signed on for the off-season first half with Cardenales de Lara in Liga Venezuela Beisbol Professional. He finished the half 1-1, 1.71 ERA, 21 IP, .76 WHIP and 9 saves. Kelly again pitched for Cardenales de Lara in 2018 winter season and on November 20, 2018, converted his 19th consecutive save, a club record.[15]
Somerset Patriots (second stint)
On March 28, 2018, Kelly signed with the Somerset Patriots of the Atlantic League of Professional Baseball.[16] On July 14, Kelly earned his 100th professional career save with three strikeouts in the ninth inning to preserve the 3–1 Patriots victory. In 46 appearances out of the bullpen for Somerset, he accumulated a 3.16 ERA with 57 strikeouts and 23 saves across 42+2⁄3 innings pitched. Kelly became a free agent following the 2018 season.
On June 22, 2019, Kelly signed with the High Point Rockers of the Atlantic League of Professional Baseball. He finished the regular season with 13 saves with 24 strikeouts in 24 innings pitched. In this, their inaugural season, the Rockers made the 2019 ALPB playoffs via wild card. Kelly became a free agent following the season.[citation needed]
On November 22, 2019, Kelly signed with the Acereros de Monclova of the Mexican League. Kelly did not play in a game in 2020 due to the cancellation of the Mexican League season because of the COVID-19 pandemic.[17] He later became a free agent.