shammari started his football career at the age of 12 when he joined the junior team of al gharafa under the guidance of hassan afif (the father of ali afif), who was then the youth coach of al gharafa. he advanced rapidly through the ranks of al gharafa, until he reached the first team in 1999 at the age of 16, the youngest footballer in the qatar stars league at that time. shammari helped al gharafa win the league three consecutive times from 2008 to 2010. in the 2008 season, he scored a goal against al sadd, who were then second in the league, in the 4th minute of extra time to draw the game 1-1 to ensure al gharafa stayed in first place.