Coming from a sporting family background with his father Sunil Kumar being a former state-level boxer, Sindhu started playing cricket in his formative years and made significant strides in domestic cricket for Haryana in younger ranks at first. He first broke into the scene for Haryana in Under-14 Dhruv Pandove Trophy in 2017. He scored 290 runs and bagged 24 wickets in the tournament. Later on in the 2017-18 Vijay Merchant Trophy, in the Under-16 side, he again fizzled scoring 280 runs and taking 16 wickets. Once again he rose to the occasion in the tournament and helped the country win the tournament. In the 2022 Under-19 World Cup in West Indies, Sindhu took 6 wickets from 5 games and hit a century in the final match against England to help the side lift the trophy. His meteoric rise tempted the IPL franchise fighting for his signature and Chennai Super Kings signed for Rs 60 lakhs ahead of the 2023 edition.