"The nation of 2.2 million faces the huge challenge of forming a competitive national football team by 2022.
"However, this cannot be achieved by quickly naturalising players," Blatter said in his Fifa Weekly commentary.
Qatar has just 282,750 citizens, although it hosts an estimated 1.5 million expatriates.
Blatter warned that Fifa would monitor Qatar's selection process.
Under Fifa rules, a player has to have been born in the country he represents or his parents have to have been born there.
Otherwise, the player must have spent at least five years living there to qualify.