Hassan joined Army United F.C. for the 2015 Thai Premier League season. He made his debut in a 1-0 win over Royal Thai Navy F.C. After a series of games in good form Hassan excelled in a surprising 1-0 away win at Suphanburi F.C., handing the latter side their first home defeat of the 2015 season as well as giving Hassan man-of-the-match award. After the game, Suphanburi player Jakkaphan Pornsai said Hassan's performance was the main reason Suphanburi lost the match. In November 2015 Hassan signed a new two-year contract with the club. He excelled so much so that British newspaper The Telegraph placed him 18th in their list of top 20 goalkeepers worldwide in 2016. In December 2016 after the relegation of Army United from Thai League 1, Hassan Sunny was released from the team, ending two years of service at the Thai club.
