A mobile 195cm key forward from Moama and the Bendigo Pioneers, Shanahan broke into the West Coast Eagles' senior side in round 16 of 2025 and made an immediate impression with his overhead marking. He earned a Rising Star nomination in round 2 of 2026, made the AFLPA's 22Under22 squad and is contracted through to 2028. He has played 32 AFL games and kicked 41 goals.