Chelsea's England Under-21 international midfielder Nathaniel Chalobah has joined Middlesbrough on loan.

Karanka, who was Mourinho's assistant at Real Madrid, brought in Kenneth Omeruo last week and he has now moved for Blues' highly-rated defender Chalobah, bringing him to the Riverside on loan until the end of the season.

The 19-year-old spent the first half of the season on loan at Nottingham Forest and made 12 appearances.