Real Madrid have confirmed Karim Benzema has sustained a ligament injury to his right knee, ruling him out of the UEFA Champions League clash with Atletico Madrid.
The France striker missed Saturday's 3-1 win over Malaga with the problem and will also be sidelined for the second leg of Real's Champions League quarter-final.
Ancelotti had been optimistic over Benzema's fitness on Friday but dismissed suggestions there was confusion over the Frenchman's injury.
"No-one is confiused, he had an injury on Tuesday. It seemed on Friday that it was okay but he tried to work on Saturday and Sunday and his sitation didn't improve.
"The player had quite a serious injury in the first leg but did't manage to recover."
Carlo Ancelotti will also be without Gareth Bale and Luka Modric as Real seek to progress following a 0-0 with Atletico in the first leg last week.