Barcelona - Real Madrid striker Karim Benzema will miss Wednesday's Champions League quarter-final second leg against Atletico and it would be the ideal moment for Javier Hernandez to prove his worth.
The Mexican has had limited chances since his loan move to the Spanish capital from Manchester United but with Real facing an injury crisis he is set to start in attack.
Luka Modric and Gareth Bale are ruled out by injury but coach Ancelotti was hoping to have Benzema available after suffering a knee problem in the 0-0 draw in last week's first leg against Atletico.
"He (Benzema) picked up the injury on Tuesday and on Friday he seemed to be doing well. Then on Saturday and Sunday he hasn't improved," Ancelotti told a news conference on Tuesday.
"He had a swollen knee and he hasn't been able to recover.
"We have to cope with injuries, we have had them before like in the semi-finals last year. We have been without Bale, Cristiano (Ronaldo) or Xabi Alonso in the past. This is not going to affect our confidence."
Hernandez was known as a "super sub" for United in the Premier League, regularly scoring goals after being brought on in the second half but with Real's squad fully fit he has rarely even had that chance.
He spoke last month about how few opportunities he has been given and looked sharp when he came on for Bale in Saturday's La Liga win over Malaga, setting up a goal for Cristiano Ronaldo.
"Chicharito (Hernandez) has been doing well in games and looked physically strong against Malaga," Ancelotti said.