[5] Kendellen made his first start for Munster in their 10–8 away defeat against provincial rivals Connacht in round 9 of the 2021–22 United Rugby Championship on 1 January 2022,[6] and scored his first try for the province one week later in their 18–13 home win against Ulster.
[12] Kendellen represented the Ireland Schools team at the under-18 Six Nations Festival in 2018, and captained the side at the same tournament in 2019.
[14] He received his first call up to the Ireland 7s team ahead of the International Rugby 7's tournament at St George's Park, England in May 2021, where they played hosts Great Britain and the United States.
[19] Looking to get back to winning ways, Ireland suffered a scare against Italy on 7 July, trailing 23–12 at half-time, before two tries from player of the match Kendellen sparked a second-half comeback for a 30–23 Irish victory.
[22] Kendellen was selected in the Emerging Ireland squad that travelled to South Africa to participate in the Toyota Challenge against Currie Cup teams Free State Cheetahs, Griquas and Pumas in September–October 2022,[23] however, he was ruled out of the tour due to concussion and returned to Munster to complete the mandatory return-to-play protocols.