On 23 February 2023, Kelsy was a substitute during the Europa League Playoff 2nd Leg against Rennes.[5] In the penalty shootout he scored the deciding goal that took Shakhtar Donetsk to the Round of 16.[5]
On 30 April 2024, MLS side FC Cincinnati announced Kelsy's acquisition via loan for the remainder of the 2024 season with an option to buy as part of the MLS U-22 initiative program.[6] On May 11, 2024, Kelsy scored his first goal for the club as part of a 2-1 win over the Columbus Crew in the Hell is Real Derby.[7]