Boston Red Sox In 2015, Kelley played for the
rookie–level Gulf Coast League Red Sox and the
Low–A Lowell Spinners, combining to go 1–3 with a 3.60
ERA in 25 innings. He split the 2016 season between the
Single–A Greenville Drive and the
High–A Salem Red Sox, going a combined 1–3 with a 1.83 ERA in 39 innings. where through the end of June he had a 5–2 record in 28 games (all in relief) with a 0.96 ERA and 34 strikeouts in innings. he made his MLB debut on July 2, pitching the ninth inning in a 10–6 win over the
Toronto Blue Jays. Kelley was optioned to Pawtucket on July 4. In late August, he was named to the
International League post season all-star team. He was recalled to Boston on September 4, following the end of the Triple-A season. In mid-September, Kelley was named a Triple-A post season all-star by
Baseball America, and was named the recipient of the Red Sox'
Lou Gorman Award. Overall with the
2019 Red Sox, Kelley appeared in 10 games, compiling an 0–3 record with an 8.64 ERA and six strikeouts in innings.
Philadelphia Phillies On December 2, 2019, Kelley was claimed off waivers by the
Philadelphia Phillies. He was designated for assignment following the acquisition of
Reggie McClain on January 31, 2020. Kelley cleared waivers and was sent outright to the Triple-A
Lehigh Valley IronPigs on February 5. Kelley made the
Opening Day roster for the Phillies in 2020. In four appearances for the Phillies, he struggled to a 10.80 ERA with five strikeouts across innings pitched. Kelley was designated for assignment again by the Phillies on August 11. He cleared waivers and was sent outright to Triple-A on August 15. Kelley elected free agency on September 28.
Chicago Cubs On December 21, 2020, Kelley signed a minor league contract with the
Chicago Cubs. On April 24, 2021, Kelley was released by the Cubs organization.
Atlanta Braves On April 28, 2021, Kelley signed a minor league contract with the
Atlanta Braves organization. Kelley spent the season with the Triple-A
Gwinnett Stripers, making 37 appearances with a 1.52 ERA and 46 strikeouts. He elected free agency following the season on November 7.
Milwaukee Brewers On November 18, 2021, Kelley signed a minor league deal with the
Milwaukee Brewers, with an invite to spring training. He had his contract selected on May 17, 2022. On the year, Kelley made a career-high 18 appearances, logging a 6.08 ERA, striking out 23 in innings of work, and collecting his first career win. On January 4, 2023, Kelley was designated for assignment by the Brewers following the acquisition of
Bryse Wilson. On January 11, Kelley cleared waivers and was assigned outright to the Triple-A
Nashville Sounds. However, he rejected the outright assignment and elected free agency the same day.
Tampa Bay Rays On January 18, 2023, Kelley signed a minor league contract with the
Tampa Bay Rays organization. On February 16, Kelley was selected to the 40-man roster, but the move was voided the following day as, as a non-roster invitee, Kelley was ineligible for the 40-man until March 15. On March 15, the Rays officially selected Kelley to the 40-man roster, placing
Andrew Kittredge on the 60-day injured list to clear roster space. He was optioned to the Triple-A
Durham Bulls to begin the 2023 season. On May 12, 2023, Kelley made his first major league start against the
New York Yankees. In 10 games for Tampa Bay, he registered a 5.87 ERA with 11 strikeouts in innings of work. On September 22, Kelley was
designated for assignment following the promotion of
Junior Caminero. He cleared waivers and was sent outright to Durham on September 24. Kelley elected free agency following the season on November 6.
Seattle Mariners On February 23, 2024, Kelley signed a minor league contract with the
Seattle Mariners organization. In 54 appearances for the Triple-A
Tacoma Rainiers, he compiled a 3-2 record and 3.52 ERA with 62 strikeouts across innings pitched. Kelley elected free agency following the season on November 4.
Leones de Yucatán On March 19, 2025, Kelley signed with the
Leones de Yucatán of the
Mexican League. He made 54 appearances for Yucatán, compiling a 3-0 record and 4.47 ERA with 43 strikeouts and two saves across innings pitched. On April 6, 2026, Kelley was released by the Leones.
Tigres de Quintana Roo On April 14, 2026, Kelley signed with the
Tigres de Quintana Roo of the
Mexican League. ==References==