On 31 January 2023, Lindberg confirmed, that he had joined Danish 3rd Division club Ishøj IF.Ishøj opruster markant: Henter Kristian Lindberg på en kort aftale, bold.dk, 31 January 2023 He made his debut for the club on 18 March, replacing Daniel Stückler in the 63rd minute of a 2–0 league victory against AB Tårnby. Three days later, he scored his first goal for Ishøj in a 1–1 home draw against Næsby, and he scored his first brace nine days later, on 1 April, helping his side to a convincing 6–0 win over Dalum.
