The Green Bay Packers’ plans to get their once high-octane, blur of an offense back on track were supposed to start with the return of Pro Bowl wide receiver Jordy Nelson from a torn ACL in his right knee.

But those hopes and plans may be on hold as Nelson and several other key offensive contributors were listed on the Packers PUP (physically unable to perform) list before the first training camp practice on Tuesday due to what Nelson described as a “hiccup” to his left knee.

While choosing not to elaborate on the new injury, the 31-year-old Nelson did his best to quell any fears about another ACL tear or serious injury, but also stressed that his recovery timeline is strictly for Week 1 of the upcoming season when Green Bay opens at the Jacksonville Jaguars.

"We put a timetable on the ACL and thought we'd be back," Nelson said, "but obviously something happened with the other knee. Again, not the ACL. No one needs to freak out. That's what we're trying to get out there. If we put a timetable on it and something else happens, then I lied to you. It's something that we'll just let progress, and as it gets better we'll do more and get back as soon as possible.

"I'm not worried about it. That's the great thing. If it was something more serious, I'd kind of be a little more nervous. It's something that's not a big deal. Obviously, everyone likes to be healthy, and I've already had a year off. So I don't need any more time, but it's part of the game."

It’s unknown how or when Nelson suffered the latest knock, but it’s clear Green Bay’s offense wasn’t the same without him last season. In 2014, Nelson logged a career-high 98 receptions for 1,519 yards and 13 touchdowns, and Green Bay ranked first in points scored and net yards per pass, as well as eighth in passing offense. But once Nelson went down during the preseason and missed all of 2015, Green Bay plummeted to 19th in points, 25th in passing, and 31st in net yards per pass.

Those numbers can’t all be contributed to Nelson’s absence. Quarterback Aaron Rodgers battled through injuries and was terrorized behind the line of scrimmage, while running back Eddie Lacy dealt with fitness issues and receiver Randall Cobb was also hurt.

But Nelson’s return would’ve acted as both a figurative and literal catalyst to the once glorious offense, while helping them battle the rising Minnesota Vikings for a fifth NFC North crown in six years.

Green Bay head coach Mike McCarthy said he had no “long-term” concerns about any of the six players on the PUP list, but the majority of the list could effect the Packers offense going forward. Freshly signed tight end Jared Cook, second-year wide receiver and returner Ty Montgomery, guard T.J. Lang, center Corey Linsley, and line backer Sam Barrington were also listed.

And Rodgers admitted Nelson’s absence was a major detriment to last year’s flatlining, specifically how Green Bay couldn’t stretch the offense without Nelson’s rangy speed.

"A lot of that was predicated on Jordy Nelson," Rodgers said. "We had a lot of single-receiver, or two-receiver, max-protection plays with him and taking some shots down the field. When you're hitting those 60-, 70-, 80-yard chunk plays, it's going to make your play-action stats and averages and touchdowns look a lot better. Getting him back, and then also getting some other guys to do some of the same stuff so the pressure isn't all on him to run those routes, is going to help us get back to where we need to be.

"He's a special guy."

Still, there is time for Nelson to rest and heal and McCarthy’s unlikely to push him in the preseason.

The Packers open the preseason against the Indianapolis Colts with the Hall of Fame game in Canton, Ohio on Sunday, Aug. 7, and then face the Cleveland Browns five days later at Lambeau Field.