"At the end of the Tri-Nations, if I am not happy, then it will perhaps be time to retire from international rugby," said James, who made his South African debut in 2001.
"Form is what counts and if I am not going to be in the plans for the British Lions tour next year, which is a major carrot for me, then I will move on from the Boks and concentrate on finishing my career with Bath."
James joined Bath from The Sharks after the conclusion of the victorious 2007 Rugby World Cup campaign and has now suggested that he may turn his back on the Boks in order to concentrate on his club career.
"They want to talk to me about an extension on my contract when I get back, and from their point of view it would be easier if I was no longer involved with the Boks.
"I signed a two-year deal with Bath and have never had any intention of dishonouring my commitment to the club. I would not let them down by going back on my word."
Despite possible retirement being just over a month away at the conclusion of this year's Tri Nations, James says that, for now, his mind is focused on retaining the Springbok stand-off spot and playing his way back into form.
"I need to know whether I am going to be good enough to play for the Springboks next year.
"I have not been playing well. I'm the first to admit that, but I think people are getting carried away with the way they are writing me off and I hope to get an opportunity soon to prove the critics wrong.
"I did not play well against the All Blacks, but was better against Australia. It has only been a few games. A dip in form happens to nearly everybody. Also, the backline did not get good ball in those games.
"I don't enjoy it when I am not playing well and not keeping up and I am very keen to get a chance to prove to myself that I have still got it.
"The desire is the same. There is the same massive excitement on match day and huge pride when I pull on the jersey."