After graduating, Castronova participated in numerous pro days, combines, local days, and showcases in an attempt to gain the attention of a
NFL,
CFL, or
XFL team, but was not signed by any.
Carolina Cobras (NAL) Finally on November 12, 2019, he signed with the
Carolina Cobras of the
National Arena League. After the cancellation of the 2020 NAL season due to the
coronavirus pandemic, Castronova re-signed with the Cobras before the 2021 season.
Albany Empire (NAL) Castronova signed with the
Albany Empire in 2022 and took over as the team's starting quarterback in the second week of the season. During the season, he led the Empire to their second National Arena League title in two years. He also won four offensive player of the week awards while passing for 2,639 yards and 58 touchdowns, both second in the league. Castronova also led the league with 226 rushing yards and 15 rushing touchdowns.
Jacksonville Sharks (NAL) After being released by the Albany Empire, Castronova quickly signed with the
Jacksonville Sharks and led them to the league title game. On August 12, 2023, Castronova led the Sharks to a 54-45 victory over the Carolina Cobras in the 2023 NAL title game. He earned recognition as the Championship Game MVP after passing for 241 yards and four touchdowns and contributing two rushing touchdowns. Castronova was also named NAL MVP after the season.
San Antonio Gunslingers (IFL) On October 2, 2023, the
San Antonio Gunslingers signed Castronova. Through 16 games with the Gunslingers, Castronova led the
IFL with 3,346 passing yards and 75 passing touchdowns and also added 23 rushing touchdowns to his total. He was named
Offensive Player of the Year at the end of the season and was recognized with
First-team All-IFL honors. In the playoffs, he led the Firebirds to win the inaugural Arena Crown Championship. He was named the 2025 AF1 MVP after the season.
Tulsa Oilers (IFL) After concluding the AF1 season with the Firebirds, Castronova signed with the
Tulsa Oilers of the
Indoor Football League on July 14, 2025. He led the Oilers to a playoff berth while completing 64% of his passes for 520 yards and 14 touchdowns.
Memphis Showboats (UFL) On August 11, 2025, the
Memphis Showboats signed Castronova to a contract as part of a group signing of four of the Firebirds' core offensive players. The team would fold later that year before Castronova appeared in a game for them, and the quartet went unclaimed in the subsequent
2026 UFL draft.
Albany Firebirds (AF1) (second stint) In January of 2026, Castronova re-signed with the Firebirds.
Albany Firebirds (AF1) (third stint) On May 6, 2026, Castronova re-signed with the Firebirds. == Personal life ==