Just last month, we brought you the news when Academy Award nominee Jessica Chastain (The Help, Lawless) entered negotiations to join the cast of director Shane Black‘s forthcoming installment of Marvel Studios‘ wildly successful Iron Man franchise, opposite Robert Downey Jr., Guy Pearce and Ben Kingsley.

Now, Chastain herself has announced via her Facebook page, that she will not be joining the cast due to scheduling problems. Chastain said,

“Sorry to say that Iron Man 3 isn’t going to work out. My schedule is jammed packed and I can’t fit anything else in. The press announced my possible attachment far too soon. I know many of you wanted me to be involved, and I’m so sorry to disappoint you. Hopefully there’ll be another Marvel film in my future. Shane Black and everyone on the IM3 team are really wonderful. I’m very excited to see the film when it comes out. xx”

That means the search is on for another “sexy scientist every bit as smart as Tony Stark“. Diane Kruger, Gemma Arterton and Isla Fisher were previously considered for the role.

Iron Man 3 is slated to hit theaters on May 3rd, 2013.