Without them, the Packers' run defense was sliced and diced. They ranked 31st in the 32-team league until Sunday's stellar effort against Detroit.
Jackson lined up with the first-team defense, though Packers coach Mike Sherman said he likely wouldn't be ready for game action until the following week. Lee, according to Sherman, has a better chance of playing Sunday against Dallas than does Jackson.
While most of Wednesday's practice was conducted without pads, Lee and Jackson spent their day in full pads, banging with a couple of offensive linemen.
"We came out of this game offensively with so many offensive plays that I took the pads off today, particularly because we have some injuries and I want to have a fast practice," Sherman said. "But those guys are going to have some pads on and are going to be banged around a little bit, speaking of Grady Jackson and James Lee, and then see how they are tomorrow, see how they respond to the contact of being hit on in a practice controlled environment.
"Tomorrow we see if there's any swelling, significant decrease in their ability to function. That will help me make a decision on Sunday. I'd say (Jackson) is more like a week away, to be honest with you. I don't anticipate (Jackson returning) this week. He does, but I don't."
Jackson, indeed, thinks he'll play.
"I feel like if I feel well. I'm ready to go," said Jackson, who was expected to be out of action for 4-6 weeks. "I just have to see how I feel. I just have to wait until tomorrow, see if I swell up or anything, stuff like that."
So far, so good, said Jackson.
"Yeah, I felt pretty good in there. I was kind of hesitant that first play, just trying to get the feeling back," Jackson said.
What Jackson provides to the team is obvious to even the most novice of Packers fans. At a supposed 340 pounds, Jackson is huge, powerful and able to control the middle of the defense.
"Just clogging up that middle," Packers safety Darren Sharper said when asked how Jackson helps the defense. "Not having the open lanes that we've had. Just having experience back at that position and you have more bodies and adding more depth, which is going to be a good thing for us as a team. Everyone knows what Grady does as far as controlling the line of scrimmage, taking up two gaps. In our defense, that's what we need."
In yet another dose of good news, second-year cornerback Chris Johnson returned to action Wednesday.
Johnson, a standout performer as a seventh-round draft choice during the 2003 training camp, was lost for that season late in training camp after injuring his right knee. He appeared to be on the road to recovery during this spring's minicamps, but he suffered a stress fracture in the same leg.
That landed the speedster on the physically-unable-to-perform list, putting him out of action for six weeks. Those six weeks are over, and the Packers get another three weeks before having to decide whether to put Johnson on the 53-player active roster, release him or put him on season-ending injured reserve.
Sherman just wants to see Johnson, who was drafted on potential instead of production based on a less-than-stellar career at Louisville, in action.
"You know, I keep on waiting for Chris Johnson to come back, assuming that he's been playing a lot of football previously. But he really hasn't played a lot of football," Sherman said. "He had great minicamps when we had him in the minicamps. We're very excited about him. He had a good preseason before he got hurt. And it's unfortunate he did. But it will be good to get him out there. He's a talented athlete that I think has a bright future."
Johnson was excited to get back to work.
"I'm excited. I know I'm going to be kind of shaky at first but once I get the hang of things I think I'll be back to my old self again."