American Idol champion Kris Allen has been forced to pull out of a scheduled appearance on The Tonight Show with Conan O’Brien this Wednesday following the death of his grandmother.

“I know I was supposed to do conan on wed, but there was a death in my family,” Kris announced on his Twitter Monday.

The Arkansas native, who is currently hitting arenas across the country as part of the 2009 Idols Live Tour, will be replaced by Idol runner-up Allison Iraheta.

Allison “is filling in,” Kris Tweeted. “And by filling in I mean [Allison] is gonna rock Conan’s face off on Wednesday.”