*Club domestic league appearances and goals, correct as of 07:54, 16 September 2022 (UTC) ‡ National team caps and goals, correct as of 16 September 2022
Aizil would go on to make his professional debut against the same side Tampines Rovers in a 4–2 win over The Stags making him the second-youngest goalkeeper debutant in the league's history at 17 years and 218 days old, just falling short of his father's record at 16 years and 309 days.[4]
Aizil would then make four more consecutive appearances for The Cheetahs before being unavailable during Hougang's league match against Tanjong Pagar United.[5]
Aizil was called up for the Singapore under-15 squad ahead of the 2019 AFF Championships.[10]
In 2022, Aizil was called up to the provisional squad for the Singapore under-23 team ahead of the under-23 AFF Championships[11] held in Cambodia but ultimately didn't make the cut. Aizil was then called up to the Singapore under-19 team for the under-19 AFF Championships[12][13] held in Indonesia after Hougang's AFC Cup campaign but didn't travel with the squad as he appeared on the bench against Young Lions a few days after the tournament's opening. Aizil was called up for the team again for the AFC U-20 Asian Cup qualifiers and made his debut against group hosts Tajikistan, producing a man of the match performance as he kept a clean sheet including a penalty save to give The Cubs a hard-fought draw.[14][15][16][17]
Aizil was called up for the 2023 Merlion Cup campaign where he made his Under-23's debut in a 1–0 loss to Hong Kong, along with a loss, Aizil would be awarded a red card for his behaviour against the referee near the end of the match.[18] Following his good showing in his league campaign, he was then called up for the 2023 SEA Games 25-men provisional squad.[19] He then made the final cut for the squad and made his first SEA Games appearance in a 3–1 defeat to Thailand in the group opener.[20][21] Aizil was also given the starting position in the 7-0 thrashing from Malaysia, leading to the intense criticism despite his stellar performances in goal. [22]