A two-time All-Australian at Collingwood, where he won consecutive Copeland Trophies in 2018 and 2019, Grundy joined the Sydney Swans ahead of 2024 after stints with the Magpies and Melbourne. The 202cm ruckman finished runner-up in Sydney's 2025 best and fairest and earned another All-Australian blazer in 2026 alongside Charlie Curnow. He has played 264 AFL games and kicked 88 goals.