The Romford-born forward scored ten goals at under-18 level last season and enjoyed a positive end to the 2024/25 season after netting eight goals in the Toon Teenagers' final nine Under-18 Premier League North fixtures.
Kacey made his full debut for the Magpies' U21s side during October's Premier League 2 visit of Tottenham Hotspur as well as scoring in the UEFA Youth League against FC Barcelona.
The 18-year-old committed his future to the Magpies after signing his first professional contract this summer and will link up with Robbie Stockdale's Under-21s squad this season.
After signing his maiden pro deal, Wooster told newcastleunited.com: "It's a good feeling to sign my first professional contract and a proud moment for me and my family but hopefully it's just the start of a good career.
"Newcastle had that belief in me when I signed from Southend at 15. Now, it's just repaying the favour and performing on the pitch."