Clark then carved out a very successful playing career at Subiaco, playing in three winning WAFL grand final teams, winning the Simpson Medal as best on field as Subiaco defeated South Fremantle in the 2021 WAFL grand final, despite injuring his AC joint in a collision in the first quarter.
[3] Clark had an outstanding 2021 WAFL season, ranking first for tackles (7.3), fifth for disposals (27.1), seventh for contested possessions and twelfth for score involvements, finishing equal third in the Sandover Medal.
[6] Clark was expected to make his debut in Round 1,[7] but hurt his AC joint that he injured in the WAFL grand final, leading him to miss 8–10 weeks.
After another strong performance in the WAFL, Clark was named on the Interchange for West Coast's round 7 fixture against Richmond, becoming the 12th Eagle to debut that season.
[8] Despite West Coast's 109 point defeat, Clark had a promising debut collecting 24 disposals and tackling 6 times.