Training camp has started for the Giants but not for Jason Pierre-Paul who is here in body but not so much in spirit.

“Honestly I don’t feel a part of the team now with them being out there and doing all the work they are doing’’ Pierre-Paul said yesterday. “I will be on the sideline through it all.’’

It brings a shudder to the Giants and their fans to think of Pierre-Paul as not part of the team but for now that’s the way it is. Pierre-Paul called having a back problem “a really really horrible thing to have’’ and although he says he no longer is in any pain following surgery and estimates he is 75 percent healthy he offered no promise he will be ready to play in the Sept. 8 regular-season opener in Dallas.

“A back is a really really horrible thing to have back surgery period and you don’t want to rush back’’ Pierre-Paul said before the Giants hit the field for their first practice of camp. “I’m not concentrating on the first game the second game the third game fourth game fifth game sixth game. I’m just trying to come back when I feel like I’m ready to come back.’’

That’s not exactly what Giants fans want to hear from their star defensive end but that is the reality of the situation. Pierre-Paul is just 24 years old but on June 4 underwent a microdiscetomy to repair a herniated disc in his lower back. The Giants at the time estimated his recovery time at 12 weeks which kept alive the hope JPP could find his way back to the field for the first game. That could happen but it’s far more likely it won’t and he is not making any guarantees.

“I don’t know only time can tell’’ Pierre-Paul said. “It’s all on me to recover. I can’t promise nothing. I can’t say I will be back for the season opener.”

After his overwhelming 2011 season when he erupted for 161/2 sacks and was a terror virtually every game Pierre-Paul’s sacks last season dropped to 61/2. He said in order to not miss any games he took three epidural injections to dull the pain in his lower back and clearly was not physically able to inflict his usual damage. He said it was painful when he got down into his stance and his back also hurt when he drove in a car for more than 30 minutes or simply when he stood up.