Gavin Dunayski was ranked by 247 Sports as the No. 22 overall recruit from the state of Washington in the 2017 recruiting class. Dunayski was also given a three-star ranking by 247 Sports. He earned First Team All-South Puget Sound League honors his senior season. As a team captain, Dunayski helped lead Puyallup High to the first round of the 2016 4A State Playoffs, the largest classification in the state of Washington. A versatile player, Dunayski played primarily defensive end as a senior after playing defensive tackle his junior season. He also played tight end at Puyallup High. He played for head coach Gary Jeffers.
Dunayski was also recruited by Hawai'i and Yale.