Chelsea boss Antonio Conte is convinced by the quality of Ethan Ampadu.
Conte says Ampadu will start in their FA Cup replay with Norwich City.
"He will start as one of the three central defenders," said Conte.
"He deserves to play. He's showing that in every game I make this decision, like against Everton and Bournemouth. He's shown me he is ready to play with the right concentration and be ready physically and tactically to play at this level.
"It's unusual for a player who is only 17 but that shows age is not important if I give you the chance to play and you repay me with a great performance. We are talking about a really great prospect for Chelsea for the present and future."