GREEN BAY - The Green Bay Packers drafted Kenny Clark and Dean Lowry with the hope they could provide some meaningful snaps when the regular season rolled around.

But the truth is they knew it was going to be absolutely necessary.

Thanks to a poor decision emerging defensive end Mike Pennel made during the offseason, they are stuck. The four-game suspension Pennel will serve to start the season, the result of a second violation of the NFL’s substance abuse policy, has forced them to raise the learning curve.

Heading into the third exhibition game Friday night at San Francisco, their plans are shaky. Neither Clark, who is battling a back injury, nor Lowry has shown signs of being ready to play more than a bit part in the defensive line rotation.

And that’s not a good thing because minus Pennel, there are a lot of snaps to be made up the first month of the season.

“It’s part of the deal,” Pennel said of the responsibility he bears. “I’ve talked to the coaches and all of that. Our young guys are already being prepared. Being away from the guys for that long is going to suck. but I’m trying to take a little bit of positive out of it.

“I never want to be in this situation ever again and just learn from it.”

Even if the Packers force linebackers Datone Jones and Julius Peppers to revert back to defensive linemen, it probably won’t be enough to fill the void Pennel has left.

Jones dropped down below 290 pounds to help him transition to linebacker and Peppers has lost a good deal of the run-stopping ability he once had, leaving the 6-2 1/2, 312-pound Clark and the 6-5 1/2, 296-pound Lowry the Packers’ best options to complement starters Mike Daniels and Letroy Guion.

If the 6-4, 333-pound Pennel were there to play with Daniels and Guion, the Packers would have plenty of size and strength in their 3-4 base front. In the nickel package, where only two defensive linemen are used, they could put Guion and Pennel on the field on early downs and feel OK about playing the run.

The most vexing part of their predicament is that Pennel has shown signs of being the massive force at defensive end the Packers once thought he would be at nose tackle. His play in the two exhibition games has been mostly late in the game against backups – the most important snaps go to those who can play when the season starts -- but it has been impressive just the same.

He has had the best camp of his career.

“I mean yeah, but the elephant in the room is that I can be happy about all this, but I’m still going to miss four to five games,” Pennel said.

After being asked to move from nose tackle to end in the middle of training camp last year, Pennel struggled to find his place. He wasn’t used to working on the edge against athletic tackles who seemed to know his every move.

He averaged 17 1/2 snaps a game and played sufficiently against the run, but his pass rush was not impressive and he offered little to the sub packages where he would have to move from end to one of four alignments inside.

“You’re out there against the most athletic guys on the offensive line, coming across Tyron Smith, Russell Okung, Greg Robinson,” Pennel said. “You just have to plan for a lot more. There’s a whole different playbook out there. The coaches reassured me throughout the weeks and into the season that they felt it was something I can handle so we ran with it.

“Then I had the whole offseason to work on pass rush, different looks, moving around. I had to really come to terms that I might not be lining up at nose every time or might not be lining up at end every time in the game, so just trying to become as versatile as possible.”

Lowry is facing much the same thing that Pennel did last year. An end at Northwestern, the fifth-round pick has had to adjust to shifting inside in the nickel package where strength matters more than quickness.

He faces the same challenges every rookie defensive lineman does when he gets to the NFL, which includes facing better talent, having to play different alignments and understanding exactly what it is the defense is trying to get done.

“He’s a smart kid,” Jones said. “Real long. He’s going to be real strong. I can’t wait to see him two years down the line when he grows into his body and really starts maturing. You’re going to see his best game.

“Right now, he’s learning. The game is going to be fast from the start. He’s going to do well.”

Lowry is starting at end in the base defense and playing a lot inside in the nickel to get experience. As it stands now either Lowry or Clark will have to team with or Guion on early downs in the nickel in place of Pennel.

The only other option is for Jones and Peppers to help fill those spots, but ideally they should only be inside on passing downs.

“If that’s where they need me, that’s where they need me,” Jones said. “It’s my former position and at the end of the day I’m still paying attention to all the calls and make sure I understand everything so I can be thrown in there.”

If Clark doesn’t play at San Francisco, it will be a huge blow to his development. He has been a non-factor so far despite being given tons of practice snaps and the only way he’ll get better is to keep playing.

The Packers can’t afford for his back injury to linger. There’s a lot of pressure for the 20-year-old first-round pick from UCLA to mature quickly and be a complement to Daniels and Guion.

He insists there’s enough time for him to get where he needs to be.

“I’ll be ready,” he said. “I’ll definitely be ready. The only thing I can control is going out there and working (hard). That’s just what I’m going to do. We’ve got three, four weeks until that time, so I’m not worried about it.”

The Packers, on the other hand, have plenty to worry about. Pennel’s suspension has left them shorthanded.