New York Giants star defensive end Jason Pierre-Paul is uncertain whether he'll be ready for the first game of the regular season against the Dallas Cowboys, estimating his capabilities at 75 percent.

It's a long road back for the Pro Bowl pass rusher from to a complete recovery from back surgery.

"I don't know, only time can tell," Pierre-Paul told reporters. "It's all on me to recover. That's everybody's goal who is hurt. I don't know. I can't promise nothing. I can't say I will be back for the season opener."

Pierre-Paul is on the physically unable to perform list after undergoing back surgery in June.

He's had back problems for the past few years, but the surgery may have done the trick to repair an issue that he attributes falling from 16 1/2 sacks in 2011 to 6 1/2 last season.

"The whole discomfort is gone," Pierre-Paul said. "When I sit down I don't have that pain any more. When I am standing up I don't have that pain. I can stand up straight. Basically everything is gone. That's a good thing. I am doing pretty good. I am happy I did the surgery.

"Now there is nothing holding me back when I do get back. At the end of the day, it was pain. As a defensive lineman, when you get in your stance, that hurts, you know what I mean, for the pain I had, that hurts. I didn't complain, I just dealt with it and played."

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Aaron Wilson covers the Ravens for The Baltimore Sun.