The centre-back has won a host of trophies during his time at the Camp Nou, in addition to a World Cup and a European Championship with Spain.
However, the Spaniard has been left out of the Barca team in the early stages of this season and his place in the national side has also been called into question despite being just 27 years of age.
"I feel that, for a while, I have not been valued for what I have done sportingly," he told reporters at a press conference.
"I have been learning more and more every year. The years remaining in my career will be the same. I say that calmly because I work hard every year.
"I always try to do the best I possibly can. I am happy with the level I have shown in the minutes I have played. I can't do anything about public opinion."
At Barcelona, Pique has won La Liga four times, the Copa del Rey twice and the Champions League twice.