The Brazilian-born Emerson has returned to Al Sadd for his second stint - having featured for French Ligue 1 side Stade Rennais. The 29-year-old played two seasons for the Qatar League side before leaving to ply his trade in France. But he failed to settle at Rennais and featured only six matches for the club.
After being given Qatar citizenship, Emerson has set a number of lofty targets. It includes winning the AFC Champions League and qualification for the 2010 FIFA World Cup in South Africa.
"My return this time is for different reasons as previously I was a foreign player while I'm here now to represent the Qatar national team," he said.
"I know that the job will not be easy but I will try my best to help Qatar to qualify for the 2010 World Cup. I also hope to help Al Sadd to win the AFC Champions League title. There is the Qatar Crown Prince Cup and Emir Cup and I will try my best to win those titles with my teammates."