Chelsea boss Andre Villas-Boas says he knows his job will always be subject of speculation.

Real Madrid coach Jose Mourinho has been linked with a return to Chelsea this week.

"Firstly, I don't think managers should speak about other manager's positions because that is a matter of ethics," he told chelseafc.com. "But just like there is speculation that surrounds player transfers, there is also speculation about managers as well, that is perfectly normal, and that is part of football.

"Speculation will always come when you are unsuccessful, and you are unsuccessful at Chelsea if you don't finish first. Managerial changes occur in all countries and at all clubs so it's normal, but it depends on the belief in the project and we have a lot of faith in what will happen here next year."