The 34-year-old openside flanker, who has been carefully managed over the past two campaigns, enters the global tournament on 142 Test appearances.
And on the back of lifting the Bledisloe Cup, McCaw admits that if he feels mentally and physically fresh after the 2015 World Cup, he could play on.
“I haven’t shut the door totally because I wasn’t sure how I’d feel come the end of October,” the experienced Crusaders flanker told the New Zealand Herald.
“I really wanted to make sure I didn’t get caught up in the ‘it’s your last game here, last game there’ stuff.
“The door is open a little bit but I just want to concentrate on what I’m doing now and get a bit of separation after the World Cup.”
He added: “I’ve done the same thing for so many years. To all of a sudden be having to figure out something else to do is a bit daunting.
“Conversely, a lot of people at this age change careers. It’s a big decision that they don’t have to make, but they choose to. The only difference is it comes to us whether we want to or not.”
Not playing rugby will be difficult for McCaw and while he is realistic, he revealed that being in the stands will be tough.
“It was always going to come to an end at some point,” he said.
“When that comes there’ll be something else I’m sure, it’s a bit of a double-edged one really.
“There’s no doubt when you start having to watch a few games, I’ll miss it like hell.”