The Irish Open has been moved from its traditional date two weeks after the Open to three weeks before the year's third major to avoid colliding with the 2012 London Olympics.
The Maryland tournament which falls on June 28-July 1 will be played on the course where the 22-year-old famously won the US Open in June this year.
"I haven't made a decision yet as to where I am going to play that week," McIlroy told Sky Sports at the World Cup on Wednesday.
"That stretch between the US Open and the Open is the only stretch in the first part of next year I have not decided on.
"I don't know what will work better for me; playing links golf before the Open or playing in the French Open or the Scottish Open.
"It's a tough one and I know I need to decide what I am going to do because the people in Ireland want to see me play in the Irish Open and if I don't play I know there will be a lot of comment.
"I am very conscious that the Irish Open needs home-grown support. It needs that support to guarantee the future, but then again Congressional will always have so many happy memories for me.
"It's something I know I have to decide on."
