Coming through the youth system, Haidar began his senior career in 2008 at hometown club Tadamon Sour, before moving to Safa in 2011. After two seasons Haidar moved abroad, first to Al-Ittihad and Al-Fateh in Saudi Arabia, then to Amanat Baghdad in Iraq. He returned to Safa in 2015, before joining Ahed the following season.
Haidar represented Lebanon internationally since 2011, playing in the 2019 AFC Asian Cup, Lebanon's first participation through qualification. He also played in the 2014, 2018, and 2022 FIFA World Cup qualifiers, and 2015 and 2019 AFC Asian Cup qualifiers.
In summer 2011, Haidar joined fellow-Lebanese Premier League side Safa in a deal worth USD$105,000.[4][5] He became a key player for the team, helping them win two consecutive league titles in 2011–12 and 2012–13.[6][7] Haidar also won the Lebanese Golden Ball in 2013.[8][9]
2013–2014: Loans abroad
In summer 2013, he moved to Saudi Arabia to play for Al-Ittihad on loan.[10] He made his debut on 13 September 2013, helping his team defeat the league title holders Al-Fateh.[11] In January 2014, Haidar moved to Al-Fateh on a six-month loan.[12] In summer 2014, Haidar moved to Iraqi Premier League side Amanat Baghdad on a one-year loan.[3][13]
2015–2016: Return to Safa
In summer 2015, Haidar returned to Lebanon to play for Safa, and won the Lebanese Premier League 2015–16.[6]
Ahed
In summer 2016, Haidar moved to Ahed on a five-year deal worth $670,000.[3] He became the second-most expensive Lebanese player in history, after Pierre Issa's transfer to Olympic Beirut in 2002 for $1 million.[3] On 8 September 2020, Haidar renewed his contract with Ahed for six years.[14]
He made his senior debut for Lebanon on 17 August 2011, in a friendly against Syria.[6] Haidar's first international goal came on 16 October 2012, in a friendly against Yemen; he helped his side win 2–1.[6] In 2013, he scored twice in the 2015 AFC Asian Cup qualification, against Thailand and Iran respectively.[6]
Initially starting out as a winger, Haidar moved to a more central role further on in his career. He is known for his dribbling and close control of the ball, as well as his set-pieces.[19]