Having previously played for AB, Brøndby and Randers at youth level,[3][4] Rajović signed for B.93 in September 2018 following a trial spell at the club.
[15] In December 2022, it was rumoured that there was transfer interest in Rajović from multiple clubs in the Danish Superliga and Allsvenskan, including IFK Göteborg.
[14][16] Having amassed 30 goals in 58 games for Næstved,[17] Rajović signed for Allsvenskan club Kalmar FF on a three-and-a-half-year deal on 9 December 2022.
[19] On 25 August 2023, Rajović signed for EFL Championship club Watford on a five-year contract for an undisclosed fee, reported to be around £1 million.
[20][21] He made his debut as a substitute in a 1–0 Championship defeat to Blackburn Rovers on 27 August,[22] and scored a brace on his first start the following week as Watford drew 3–3 away to Coventry City.