The 20 year-old has a deal to 2025 with a buyout clause of 20m.
Carcel told Mundo Deportivo: "Arnau is not playing, but he is not in the best moment to make a decision either because he is waiting for the development of his situation.
Advertisement
Advertisement
"We want him to continue, but he also needs to make a decision about what he wants to do in his career. It is an uncomfortable situation.
"I wouldn't say that the extension is at an impasse, but he also has a personal situation with his agents that he has to resolve."
The right-back has previously been linked with clubs such as Bayern Munich, Atletico Madrid, Barcelona and Bayer Leverkusen.