AUBURN HILLS – Reggie Jackson understands there are hurdles to clear before everyone believes he’s back. There might even be less than 100 percent certainty in his own mind due to the parameters of his rehabilitation from last year’s knee injury.

But without the validation of blowing by defenders he knows he should be able to pass, he’s as confident as humanly possible that he’s vintage 2015-16 Reggie Jackson, only blessed with the perspective last year’s anguish provides.

“I think it’ll be an extra confidence booster once I do so,” he grins, “but I think the old me’s back.”

So do his teammates, even though Jackson has been barred from joining them in contact drills and full-court scrimmaging during the voluntary workouts they’ve held over the past three weeks. Stanley Johnson, who like Jackson makes his off-season training base in Southern California, was in frequent contact with him this summer and his feedback has helped bolster Jackson’s notions.

“Stanley’s like my little brother,” Jackson said. “He’s told me he sees a confidence in me he saw two years ago. Just being around him, somebody I’ve grown close to over the last two years, to have guys like that around me telling me, ‘You’re looking good. You’re getting back to you. You’re jubilant and you’re free and you seem to be in a good place,’ that’s been building my confidence.”

Jackson’s been a gym rat throughout his NBA career, part of the reason he showed up to training camp last September already feeling stabbing pain in his left knee. There was none of that this summer, a 16-week rehab protocol focused on strength training and stretching but lean on drill work. He rarely touched a basketball other than to do some form shooting.

“I can never be the person that tells myself I’m working hard enough. I’ve got to be better than myself each and every day. And I had to be better by not working,” he said. “That was very uncomfortable.”

Once he was allowed to touch the ball again, Jackson was pleased at how quickly his shot came back, how natural everything felt. “Like riding a bike,” he said. In individual drills, he feels like the bounce, the lift, the first step is close to form and within easy reach.

“I’m confident I’ll be there. Still yet to play with the guys, so I’m going to have to get out here and play and show that I can get there. But from just getting back into workouts and doing a little skills work, I’m confident the burst is back and is coming back. I still have to put it into action, but I have a lot of confidence in my summer plan and the way my body feels. I’m getting comfortable, getting some explosion back, feeling good, pain free.”

Pistons physical therapist Mark Cranston spent the bulk of his summer at Jackson’s side in California to monitor his progress but also to keep a harness on him and make sure no steps were skipped in the rehab process. Jackson has been tested in every conceivable way and while he isn’t an expert on the numbers, he’s been told enough to know everything is trending positively.

“No red flags,” he said. “I’ve done quite a bit of testing. The team has the results. The numbers, from what I know, they look good. It’s just about maintaining and building that strength. There’s nothing that shows there’s anything detrimental. It made me positive, made me confident in it. Rehabbing so long without having any tests and then trying to trust in it was hard, but once I did the testing and we got to see the numbers, got to see how I move, I was like, ‘OK, I’m good. Stop worrying about it.’ Just got to be sure I’m on my regimen about stretching, about not over-pounding. Just got to be smart and wiser warming up and trust that my body is ready to go.”

Like everybody else, he’ll trust it a little more the first time he crosses over and zips past his defender to get to the rim for a layup or lob to Andre Drummond. But from everything else he knows, for everything else he’s done to get here, it’s more a question of “when” than “if” for Reggie Jackson these days.