Hassan Khalid Hassan Al-Haydos the captain of Qatar National football team began started playing football for Al Sadd at the age of eight, advancing through the ranks until he reached the first team at age seventeen. He had support and guidance early on from Jafal Rashed Al-Kuwari.

He was one of the players to take a penalty kick in the penalty-shootout against Jeonbuk in the 2011 AFC Champions League, scoring after the ball deflected off the top post. The victory ensured Al Sadd would earn a place in the FIFA Club World Cup as the representative for Asia. In the third-place match between Al Sadd and Kashiwa Reysol, he was again selected to take one of the penalty kicks after the match had ended 0–0. The penalty shoot-out was won by Al Sadd 5–3.

He was voted as the 'Best Qatari Player' in 2014 in a poll conducted by Doha Stadium, receiving 58 out of 104 votes from a panel of analysts, coaches and administrators.

Al-Haydos made his debut for the Qatar Olympic team in 2007, coming off the bench to score a late goal against Japan in the 2008 Summer Olympic Qualifiers in order to help his team salvage a 2–1 win. He featured in two other matches in the competition, one against Saudi Arabia, and one against Vietnam, where he scored a goal; both as second-half substitutes. He also played a large part in the 2012 Summer Olympic Qualifiers as the captain, scoring a goal against India in the preliminary stage. He played all the matches in the group stage, scoring a goal against Oman, and scoring against Saudi Arabia after being set up by Saleh Badr to give Qatar a 2–1 win and a glimpse of hope for qualifying for the Olympics. He won the Man of the Match award.