After appearing only seven times in the 2015 season, Najib's club head coach Steve Kean advised him to switch to the left-back position for him to gain playing time (as he has done to Helmi Zambin and Aminuddin Zakwan Tahir). A season-ending injury to first-choice Sairol Sahari meant that he would be relied on much more heavily in 2016.[4]
Najib regained his place at the start of the 2019 campaign under Adrian Pennock.[8] He was rotated with Abdul Mu'iz Sisa for the position on the left of Pennock's 3-5-2 formation, becoming the starter towards the second half of the season. He became Singapore Premier League champion with DPMM by September of that year.[9]
Despite playing in the occasional advanced left-sided role for DPMM, Najib's first league goal for the club did not come until 4 July 2021 when he scored one of the 15 unanswered goals against Rimba Star FC in the Brunei Super League.[10]
In 2022, DPMM competed domestically at the 2022 Brunei FA Cup, managing to advance to the final of the competition with Najib appearing regularly at the left side of the lineup.[11] On 4 December, DPMM overcame Kasuka FC 2–1 in the final, handing them their second ever Brunei FA Cup trophy.[12]
In the fifth minute of the Singapore Premier League fixture against Albirex Niigata (S) on 2 November, Najib suffered a head injury that required medical assistance after a mid-air collision with an opposition player.[13]
International career
Najib has played for Brunei Under-21 since 2005,[14] and is the only player to have played in 4 Hassanal Bolkiah tournaments, winning the trophy in 2012. He regards his injury-time free-kick against Cambodia in that year's opening match as the best goal he has ever scored.[15]
Najib's full international debut for the Wasps came in the 2008 AFC Challenge Cup qualification held in the Philippines where he played in all three games. He was also ever-present for Brunei's AFF Suzuki Cup qualifying campaigns in 2012 and 2014. For the 2016 edition he was deployed at left-back, but did not finish the game due to injury which would keep him out of the rest of the games.[16]
Najib was in the list for the 2016 AFC Solidarity Cup but initially did not travel with the rest of the squad.[17] Nevertheless, he recovered and made the starting lineup for the opening match, and kept his place at left-back for the whole tournament as Brunei finished in fourth place.[18]
Najib linked up with the Brunei national team for the two-legged 2018 AFF Suzuki Cup qualifying matches against Timor-Leste in early September 2018.[19] He started the first leg at left-back in a 3–1 loss on 1 September in Kuala Lumpur.[20] He kept his place in a more advanced role on the return leg at Hassanal Bolkiah National Stadium a week later and scored the only goal of the game.[21] His winning goal gave Brunei their first ever home win for an international game, but the scoreline was not enough to qualify for the Suzuki Cup competition proper.
In June 2019, Najib was due to link up with the national team for the 2022 World Cup qualification matches against Mongolia, but pulled himself out of contention.[22]
Although named in the 25-man Brunei squad for the 2026 World Cup qualification matches against Indonesia in October 2023,[27] as well as featuring in previous friendly matches in the year, Najib was left out of the matchday squad in both games. He was restored in the national team setup in June 2024 when the team was made up of almost entirely DPMM FC and led by their current head coach Rui Capela against Sri Lanka for two matches. He was fielded in both games as the Wasps claimed a double victory over the Lankans.[28]