Ranger this week was given a 12-month conditional discharge after admitting assaulting two police officers last year.
"I think I've been fair with him," Pardew, who gave Ranger 18 first-team chances in his first season in charge, told the Newcastle Chronicle.
"This guy is late so often, it is unbelievable. He's still at this football club and we're still trying to do something with him.
"But he will still not get back in the team unless he has a period of six weeks where he isn't late.
"I don't think it is going to happen.
"It is important, I'm not going to let him train with my first team because he is letting the other players down."
Asked if he thought Ranger would ever clean his act up, Pardew responded: "For Nile? That's up to him."