Alonso has been linked with Real Madrid, who have not hidden their admiration for the Spain midfielder, and Argentinian Mascherano is reported to be a target of Barcelona.
But in a statement on their official website, Liverpool said: "Despite repeated media speculation on the futures of Xabi Alonso and Javier Mascherano, Liverpool has received no official approach or offer from any club regarding the players."
It continued: "Neither is for sale and furthermore Liverpool has no interest in the long list of Spanish based players being linked with a move to Anfield as part of any deal."
Madrid's young strikers Alvaro Negredo and Alberto Bueno have been suggested as makeweights in any possible deal for Alonso.
However Liverpool manager Rafael Benitez considers his midfield pair to be integral to the club's plans for next season, recently stating that Barcelona "could not afford" Mascherano and that Alonso was "not for sale".