Ronaldo responded to his Ballon d'Or snub with a masterclass in the Copa del Rey.
"His goals and performance are there for all to see, and his performance the other day. What we have seen is more than enough to assess it. There are never any doubts about Cristiano," said Karanka.
"Recently when he has not been scoring as normal, the team has felt it. Now that he's back scoring, and the number of goals he's scoring and the confidence it gives him, it's important for the rest of the team."