Namazi was born in Provo, Utah, when his father, Mehdi Namazi, was attending Brigham Young University to study for a master's degree. The family returned to Iran where Namazi grew up in Tehran. When he was eighteen, his father moved the family back to the United States after the Iranian Revolution. They settled in Washington, D.C. metro area of Herndon, Virginia. Namazi attended West Virginia University where he played on the men's soccer team from 1984 to 1987. He graduated with a bachelor's degree in exercise philosophy.[4]
In March 1999, the Philadelphia KiXX fired Dave MacWilliams. Namazi, on injured reserve after knee surgery, served as interim head coach.[19] His success led to a permanent contract in July 1999. In 2001, Namazi took the KiXX to the MISL championship series where the team fell to the Milwaukee Wave. In 2002, the KiXX won the championship, defeating the Wave. Four games into the 2002–2003 season, Namazi left the KiXX to become head coach of the San Diego Spirit of Women's United Soccer Association.[20] He took the Spirit to the semifinals of the WUSA playoffs, the only season the Spirit made the playoffs. The WUSA collapsed at the end of the season and Namazi returned to playing for the Cleveland Force in October 2003. In March 2004, the Force named Namazi as interim head coach, making him the permanent head coach a month later. He took the Force to the 2005 MISL championship series, losing to the Milwaukee Wave. The Force collapsed during the off season. On September 21, 2005, Namazi became the head coach of the St. Louis Steamers.[21] He took the Steamers to the championship series where they lost to the Baltimore Spirit. The Steamers folded during the off-season and Namazi moved to California to coach youth soccer for a year. He returned to coaching indoor soccer in September 2007 with the New Jersey Ironmen.[22] On June 3, 2010, Namazi was named head coach of the Chicago Red Stars in the Women's Professional Soccer, replacing Emma Hayes.[23]
In May 2018, Namazi became head coach of Persian Gulf Pro League side Zob Ahan with signing a one-year deal. However, he and the club agreed to part ways only six months into the appointment.
Namazi then joined the technical staff of the United States U20 national team under manager Tab Ramos. In the beginning of April 2019, Namazi was also hired at the Danish club FC Helsingør. He was responsible for all scouting in North America.[30] On April 22, FC Helsingør sacked their manager, and the club announced that Namazi would take charge as a caretaker for the rest of the season.[31] On June 8, 2019, he agreed to continue as manager for the club for the upcoming season.[32] However, Namazi expressed regret two weeks later and announced that he would not continue with the Danish club and would move back to the United States.[33]