Luiz, who spent four years with the Portuguese giants before joining the Blues in a £26.5million deal in January last year, was looking forward to catching up with some old friends ahead of tomorrow night's first leg in Lisbon.

But the Brazilian insisted any loyalties to the club that brought him to Europe would end the moment combat began at the Estadio da Luz.

He said: "They'll be my mates right up to the first whistle but, after that, Benfica and Chelsea are going to be adversaries and both are going to fight almost to the death to win.

"As the ref starts the game, the fight will start."