Joselu is set to be sold by Real Madrid to Al Gharafa of Qatar.
Carvajal told AS: "Joselu is my family. He is someone very special. It makes me sad because we were together all day and we made plans. The children playing, holidays, we go together to train, on trips… But I also understand his situation.
"In the end, life has rewarded him for the work he has done throughout his career. He has come to Real Madrid. He has won a League, a Champions League being important… I understand his position. Mbappé and Endrick are coming in attack and he could have a lower level of participation. And he receives an offer that is irresistible and understandable."
Carvajal appreciates how Real have treated Joselu and Nacho Fernandez this week over their respective departures.
He continued: "The club, as one would say of a person, is a gentleman's club. It treats us wonderfully. If you are a player who loves the club and gives everything, the club responds. I have been in difficult times, with injuries or at a level that was not what I was used to and Madrid renewed my contract. They showed their support and their confidence and I will always be grateful for that.
"As Nacho said, it is a relationship with so much trust and naturalness that the club looks out for us and we look out for the club. They try to make us happy whether at Madrid or away."