McStay made his AFL debut against the North Melbourne Football Club in Round 15, 2014, playing at centre half-back.

The Kangaroos failed to score from the stoppage and the Lions held on to win by 4 points in Jonathan Brown's farewell game.

After the completion of the 2022 AFL season, McStay wished to explore free agency and departed the Brisbane Lions after 9 years.

[2] McStay injured his medial collateral ligament in Collingwood's 1-point win over GWS in the 2023 preliminary final.

[4] McStay ruptured his left anterior cruciate ligament during training and was initially expected to miss the 2024 season.