Chris Ivory wants you to know that he absolutely positively 100 percent is not prone to injury. The Jets’ recently acquired running back hasn’t practiced at all with his new team since training camp started and was limited to just 24 games over three seasons with the Saints but if you listen to Ivory the “always hurt” tag is mostly a media creation. The mere mention of it in fact makes Ivory groan and eager to change the subject. “I wouldn’t say I struggled with injuries in the NFL” Ivory told The Post yesterday after yet another workout missed to a balky hamstring that will also keep him out of tomorrow night’s exhibition opener at the Lions. “I had four or five hamstring injuries and a foot injury which is a lot but I was always able to get over the hump [in New Orleans]” he continued. “It’s always been more the media saying I was injury-prone which is frustrating. Ivory added that the Jets’ extended wait for him will end as soon as Sunday when he finally expects to practice but it’s usually safer to write those predictions in pencil instead of ink when it comes to the former undrafted free agent. Rex Ryan certainly didn’t sound reassured yesterday by Ivory’s prediction of an imminent doctor-approved return. “He knows more about it than I do right now” Ryan said. If Ryan is frustrated by Ivory’s inability to stay out of the cold tub the Jets coach hasn’t shown it. Ryan repeatedly avoided that question this week preferring to rave about Bilal Powell — the lone healthy running back of note in his team’s entire camp so far.