"I would hate to end up in a situation when I would start feeling tired midway through a qualifying campaign," the 34-year-old told reporters in Prague on Friday.
"I like to do things at a 100 percent."
"The decision is final."
"I'm sorry we failed to fulfil the potential of the team, we obviously could have done better," said Cech.
His move from Chelsea to Arsenal last year made the headlines, and so did his season.
He beat Karel Poborsky's record of 118 games for the Czech Republic and then passed David James as the man with the most clean sheets in the Premier League, stopping for now at 178, with James making 169.
With Chelsea he won four Premier League titles (2005, 2006, 2010, 2015), the Champions League (2012), the Europa League (2013) and a host of other trophies.
After 11 years with the Blues, Cech made a £10 million (.4 million) move across London to join the Gunners as he only managed seven games in the 2014/2015 season, shaded by manager Jose Mourinho's first-choice keeper Thibaut Courtois.