Barring Sergei Lyakhovich having a complete change of heart about fighting in Dortmund, Germany, Boxingtalk understands that Eliseo Castillo will step in to face Wladimir Klitschko on April 23. Klitschko advisor Shelly Finkel confirmed that Castillo would be the replacement, but "nothing is set in stone yet." Boxingtalk.com will continue to keep you updated, until then, Remember where you heard it first! (11:55 AM ET)