[4] On 16 July 2016, Al-Ahli announced that Al-Najjar suffered an anterior cruciate ligament injury.
[9] On 24 November 2020, Al-Najjar made his professional debut for Al-Wehda in the Saudi Pro League, starting in the 0–1 loss against Al-Taawoun.
[10] During the 2021–22 season, Al-Najjar made seven appearances for Al-Wehda helping achieve promotion to the Pro League.
[14] On 24 November 2023, Al-Najjar made his AFC Champions League debut in his team's 1–1 draw against Istiklol.
[15] In January 2024, Al-Najjar was called up by coach Roberto Mancini to the Saudi Arabia national team squad for the 2023 AFC Asian Cup.