The 32-year-old's debut will come during Saturday's Premier League clash against Everton following his move to Stamford Bridge from Anzhi Makhachkala.
"He will be selected and when you are selected as a striker you play - you start or finish the game," Mourinho said in a press conference.
"He will play his first minutes for Chelsea. He has natural appetite for goals and gives experience to a team from midfield to attack everyone is very, very young."
The West London outfit are currently second in the table on seven points, beneath Liverpool.