The 23-year-old was called back to Gelsenkirchen in the summer after spending two seasons on loan at Eintracht Frankfurt, and he insists he will not be dislodged from the Schalke goal.
"The fact is I am the number one at Schalke and I will not be making way for anybody," he told the Bild newspaper.
"My aim is to play at least 300 games for Schalke. I want to be the number one here for the next 10 years."
Reports Schalke are not convinced with him and are plotting to sign Germany international Rene Adler from Bundesliga rivals Bayer Leverkusen in the winter are not unsettling him either.
"I have the full faith of the board and the coaching team," he said. "Manager (Horst) Heldt has assured me that Schalke are not interested in Adler.
"All the manager has said is that Adler is a very good goalkeeper."
Indeed, Adler is good enough to be Germany coach Joachim Low's second choice when fit, but Fahrmann feels he will get enough chances this season to convince Low that he too is worthy of a place in the national team.
Fahrmann's name has yet to be mentioned in terms of the national team, but he believes that should change leading up to Euro 2012.
"There are not that many goalkeepers playing in three competitions and at such a big and important club like Schalke," he added.
"With consistently good performances, it is in my own hands to make a name for myself."