As a senior in 2018, he was the Gatorade High School Football Player of the Year for Hawaii after passing for 3,754 yards and 38 touchdowns.

[11] In his sophomore year, Gabriel led the Knights to a 6–4 record and an appearance in the Boca Raton Bowl completing 21 of 45 for 217 yards and 2 touchdowns in a 49–23 loss.

He suffered a broken left clavicle that, despite not requiring surgery, ultimately ended his season early.

[14] On December 16, 2021, Gabriel originally announced he would transfer to University of California, Los Angeles (UCLA).

[19] Gabriel proposed to his high school sweetheart, Zo Caswell on September 1, 2024, the day after his debut at Oregon.