The former Fenerbahce custodian has cut a frustrated figure for much of this term after being forced to play second fiddle to youngster Victor Valdes.
However, Rustu has now claimed Barca's number one jersey and is ready to turn his back on offers from both Germany and other Spanish clubs to prove his worth to the Catalan giants.
"When I was not playing a lot of things went through my head," the 30-year-old declared.
"I received offers from Germany - Hamburg wanted me for example - and I also had proposals from Spanish football.
"It's normal that they were interested in me because people respect, and believe, in a player signed by Barcelona.
"But I want to finish the season at Barca and then decide what I am going to do."
Rustu conceded his long-term future was less clear cut, but spelt out his desire to succeed at Barca.
"I will speak with whoever I have to speak to (in June) to see what plans the club have for me.
"But I insist that I want to see out my contract. I have a mission to fulfil at Barca."
