The Wearsiders' interest in the player was confirmed last week by Brescia, who are finalising a move for Ipswich Town's Matteo Sereni as his replacement.
Castellazi is not pleased with the developments, as he had hoped to remain as the club's number one next season.
"I have read that they want Sereni," he revealed. "And that they are trying to sell me.
"I must deduce that my services are no longer required, and the club's plans do not include me.
"Yet Brescia was my first choice.
"I know only how much the newspapers write about me and my future.
"I would want to remain in Italy, not to be on the bench, and to find a club who make my case well.
"I have a contract with Brescia that expires in June 2006, and I hoped not to have to move before that date, but evidently this will not be the case."
