One day after Nelson was placed on the physically unable to perform list, he clarified that he has an issue with the left knee -- not the torn ACL in his right knee that forced him to miss all of last season.
Nelson called it a "hiccup" with the left knee and insisted it was minor, but he couldn't put a timetable on his return. He would only say that he plans to play in the regular-season opener at Jacksonville on Sept. 11.
But at this point, it's not out of the question that Nelson won't play in the preseason.
"Our end goal is still the same," Nelson said Tuesday. "We'll be ready for the regular season. Like I said, there's just a little hiccup with the other leg.
"We're not worried about it. We're going to work through it inside and continue to progress, and we'll be ready to go at some point during camp and definitely for the season."
Nelson said he wouldn't go into details other than the ACL repair in his right knee has progressed as expected. He said he was originally scheduled to be back for the start of training camp until his left knee issue popped up.
"The only timetable is Week 1," Nelson said. "That's the only thing we're worried about. We're just going to progress as it goes. Not different from what I said with the ACL -- as things work forward, you continue to work forward with it and go from there.
"You don't ever know. Obviously I thought I'd be going right now, but you don't ever know, so things can happen and that's why you're always told it's why you don't give timelines because things can change day in and day out."
Nelson's preseason injury last year had significant impact on quarterback Aaron Rodgers, who lost his best deep threat, and the offense, which plummeted to 23rd overall and tied for 25th in passing.
Coach Mike McCarthy said earlier this week that he wasn't worried about Rodgers and Nelson regaining their chemistry. Rodgers said Tuesday he didn't think that would take long.
"Probably a couple days," Rodgers said. "He's a special guy. We're going to need a little bit of time -- not necessarily game reps, but just some reps in practice. He's going to need to feel press coverage again and getting off of that and running and making plays and catches.
"I'm confident that he'll get to a point where he'll be ready to play when we need him."