According to Sherdog:
Todd Duffee has pulled out of his heavyweight bout against Paul Buentello at UFC 107 on Dec. 12 in Memphis, Tenn., due to an injury.
"(Withdrawing) was one of the hardest decisions I’ve had to make," said Duffee, who would not disclose the nature of his injury.
The article goes on to say that Stefan Struve and Mike Russow are possible replacements to face Buentello who is fighting in the UFC for the first time since UFC 53. The injury bug is in full effect lately.