James told ESPN's Bob Holtzman that he won't return to the NFC West champions next season, even though he has a year remaining on his contract.
"I can't go through this again," James told ESPN. "I didn't come here to block. I'm not an offensive lineman."
James, who re-emerged as the Cardinals' feature back in the regular-season finale after weeks of pass blocking and barely touching the football, told reporters Thursday that his last game of the season will probably be his last in Arizona -- and that's OK.
"I think the feeling is mutual," he said, laughing. "It's not something I'm going to contest."
However, James, who had 14 carries for 100 yards in the final regular-season game, has something many of his Cardinals teammates don't have -- playoff experience. James, who appeared in nine playoff games with the Indianapolis Colts, said he intends to provide veteran leadership during Arizona's playoff run.
"When you're in the huddle and you see somebody that's not really trippin' on everything else that's going on outside of the game, that calms everybody down," James said.
James had voiced frustration with his role in the offense earlier this season, as Tim Hightower emerged as the Cardinals' feature back and James was called upon to block in Arizona's pass-heavy offense. He lost his starting job to Hightower after seven games and carried the ball only 11 times in the next eight contests.
In mid-November, James asked to be released, a request the Cardinals turned down, with team general manager Rod Graves saying, "We still saw Edgerrin as a valuable member of our football team."
"It was the direction this team went in," James told reporters. "It was something I wasn't used to. It was something I wasn't buying into. It's hard for me to train as hard as hard as I train in the offseason and come and be prepared to pass-[protect] 50 times. I don't know that you could make me happy with it."
But the playoffs push those concerns to the back burner, James added.
"They did what they had to do but at the end of the day, that's all over with," he said. "Now it's time to get serious. We're through playing around and everything is serious."
"I'm here to try to make plays and try to get this team moving forward," he said.