A torn MCL in practice is to blame for Luke Rockhold being forced out of a match up with Tim Boetsch next month at UFC 166.

Rockhold, who will be replaced by CB Dollaway, made the injury announcement on Twitter recently.

“Sorry guys tore my MCL sparring on (Friday), out 6 weeks,” Rockhold wrote. “If there was anyway I could fight I would. Was really looking forward to this fight.”

The former Strikeforce middleweight champion was looking to even his UFC mark to 1-1 vs. Boetsch, as he was defeated by Vitor Belfort earlier this year.

Rockhold’s American Kickboxing Academy teammates will still be competing on the card from Houston, as UFC heavyweight champion Cain Velasquez faces Junior dos Santos and Daniel Cormier meets Roy Nelson.