Coloccini still has three years left of the new four-year deal he signed in March 2012 but has been linked with a return to Argentina this season.
The 31-year-old returned from the back injury which kept him out for 12 games in the 0-0 draw at West Ham and he told the club's official website: "I heard that I wouldn't play because I wanted to leave and that I don't give 100 per cent.
"I don't like to speak to the press too much because I'm like that. I try to speak on the pitch and I think on the pitch I can do the things well but I always give 100 per cent.
"I love playing football. I don't think about what happens in my future - I just want to play. On Sunday we have another game. If we played on Tuesday again, I'd want to play. I always like to play on the pitch."
Newcastle's defensive record is the worst in the Premier League but victory over relegated Queens Park Rangers at Loftus Road would effectively ensure United's survival and Coloccini added: "I think it's the most impotant thing now in this situation.
"When you have bad results, you have to get confidence and I think to to have a clean sheet gives confidence to the team and gives confidence to the strikers to do their work as well.
"It will be a very tough game on Saturday. They don't play for nothing and we are playing for everything so it will be tough - but we know we have to get points."
He added: "The team knows what we are fighting and that's very important. We are fighting all together.
"When we are where we are now, you can criticise whatever you want, but when we go onto the pitch or come to the training ground, we try to do our best.
"We are together, we know what we are fighting for and we have big players who have played in the Champions League and won leagues, so nobody wants to go down here."
Newcastle's skipper paid tribute to the loyal support of the Newcastle fans in a difficult season and said: "I think they're always with us. It's normal that the passion is not like when we started the season but we have to be together because Newcastle United is not just players - it's the fans.
"Next season, the fans want to be in the Premier League so that's why they have to support us."