"I have had four extraordinary years at Chelsea until this year, which has not been very good - indeed it was the worst of my career," he said.
"I am available for a club who wishes to have me."
Carvalho joined Chelsea from Porto in July 2004 for a fee of about £20m and has played 174 times for the club, helping them to win two Premier League titles, two League Cups and an FA Cup.
But he was hampered by injuries last season, suffering knee ligament damage and a thigh problem that kept him out for almost two months.
Who do you think will leave Chelsea this summer? Carvalho admitted "I wasn't in great shape" but insisted it was because he had not played many matches.
Looking to the future, he added: "I am delighted that several clubs are interested in me. But before being approached, an agreement must be found with Chelsea."
Carvalho last played for Chelsea in the 4-4 draw with Liverpool in the Champions League quarter-final second leg on 14 April.
And he appeared to be out of favour under interim Chelsea boss Guus Hiddink, prompting his declaration of intent to move on.
However, Carvalho appeared to leave the door open for reassessment under incoming manger Carlo Ancelotti, who officially takes over on 1 July.
"If there is no transfer, I will be fine at Chelsea," he said.