If FIFA's Disciplinary Committee rule against Henry, who handled the ball in the build-up to France's crucial goal in the play-off in Paris last month that saw them secure their place in the finals, they could impose a match ban that could see him miss the start of the finals in South Africa next June.
"The disciplinary committee will open a case into the behaviour of Thierry Henry in the match against Ireland," Blatter told a news conference.
"It is not a question of it being Thierry Henry or another player. But it was blatant unfair play and was shown all over the world.
"I am not saying that Thierry Henry will be punished, what I am saying is that he will be examined by the disciplinary committee."
The disciplinary committee does have the power to ban the player and the fact a case has been opened against him suggests he could well be sanctioned with a ban from France's next competitive matches which will be at the finals.
Blatter said the disciplinary committee will also investigate trouble at the World Cup match between Algeria and Egypt and that a working group would be set up to look at the future of the World Cup qualifying competition and whether play-offs should continue.
NO CHANGE
Blatter also told a news conference there would be no change in the way matches would be officiated at the World Cup next year, with a plan to have two additional referees behind each goal not sanctioned at Wednesday's extraordinary meeting of the FIFA executive committee.
Interpol, said Blatter, would create a new Task Force to deal with illegal betting in sport and in particular in football.
Blatter surprised journalists when he said there would be no change in the method of officiating at the World Cup.
On Monday he told delegates at the Soccerex business convention in Johannesburg that two additional assistants placed behind each goal would aid the referee in his decision-making and he strongly suggested he would like to see them at the World Cup.
However, the idea, which is currently being trailed by UEFA in the Europa League this season, was not approved by the committee.
"We shall have a look at technology and additional referees, but for the time beig the experiments in the Europa League will go on but for the World Cup, there will be no change in refereeing," he said
Asked if he was disappointed by the decision, he replied: "It is not me who makes the decisions, but the committee and the International Board will discuss it next March, but there will be no change for the World Cup."
