The versatile Spain international is one of several Bilbao players who captured the attention during the club's buccaneering run to last season's Europa League final.
The 23-year-old, who can operate either in defence or central midfield, was part of his country's victorious European Championship squad and featured in the group stage win over the Republic of Ireland, with Barcelona the latest club to be linked with a move for him.
A reported 40million euro (£31.65m) buyout clause in his contract is one sticking point, but Martinez himself was keen to nip speculation in the bud before any discussions reach that stage.
"I'm very happy at Athletic," he told Spanish television channel Antena 3. "I have a contract until 2016.
"I have seen the newspapers and what it says on TV, but it is not always right.
"If you were to believe what is said I have already joined seven different teams, a different one each week. You have to ignore the rumours because they can affect you."
The club's policy of only selecting players from the Basque region engenders fierce loyalty and could be a trump card as they seek to hold on to prize assets such as Martinez, Fernando Llorente and Iker Muniain.
The restriction does not extend to the appointment of coaches, and speculation has this week surrounded the future of Argentinian Marcelo Bielsa following an angry confrontation with contractors carrying out work at the club's training ground and a subsequent disagreement with the board.
Martinez is hopeful the club have moved on from the incident and can get back to normal as they prepare for the new season.
"I'm not sure what happened with Bielsa, but the best thing for everyone is what is happening now, that everything is back to normal and the coach has devoted himself," he said.
"There has been tension but it has since subsided.
"Bielsa is among the three or four best coaches in the world, he is very good and you just have to see how we played this year."