While in college at North Carolina A&T, Junius Coston lined up at every position on the offensive line during his four-year career.

He nearly accomplished that in one practice on Tuesday.

At various times during team (11-on-11) periods, Coston took snaps with the No. 1 offensive line at three different spots - right tackle for Mark Tauscher, right guard for Jason Spitz, and left guard for Daryn Colledge. He also took reps as a second tight end in the goal-line package, and at left tackle with the No. 2 line.

The Packers are putting Coston's versatility to good use, grooming him in essence as a "super-sub" should any of the aforementioned spots need a replacement due to injury or otherwise.

"We're trying to get him possibly ready to play different spots during the course of a game," offensive coordinator Joe Philbin said. "We're just moving him around doing the best we can to give him a fighting chance, so all of a sudden we don't just throw him out there at left guard or left tackle."

That's sort of what has happened in the first two preseason games, and despite not necessarily getting to prepare extensively in a given spot, Coston has performed well. The third-year pro was a fifth-round draft choice in 2005. He spent his rookie year as a backup at left guard and left tackle, then became a right-side reserve last season.

It can be taxing, especially on a young player, to have to learn so many positions. But the coaching staff feels Coston is athletic enough and intelligent enough to handle the workload.

"It's definitely not easy, to say the least," Coston said. "It takes a lot of concentration, as far as the playbook and stuff, and a lot of concentration towards your technique. Without technique, you're not going to be good at any position."

Right now, particularly with second-year lineman Tony Moll missing significant practice time due to injury, Coston appears to be the No. 6 lineman. How much he's actually pushing the starters for their jobs isn't clear, but in working as much as he has with the first unit he's certainly doing something right.

"He's playing more physical than he ever has," Philbin said. "He generates arguably as much movement at the point of attack, at least in the films that we've watched, as any of our guys do, any of the five of them. There are some encouraging things he's doing.

"Is he quite as consistent as the other guys? Probably not. But this guy is still 23 years old. He'll be 24 in November. He's certainly had a good camp. We really like his development and we hope he continues to get better."

Aiding Coston's emergence has been good health. Last season he injured his knee in the preseason finale, wound up inactive for eight games, and played only two snaps in one game of the other eight contests.

It's hard to say when, or if, he was ever fully healthy in 2006, but his play indicates he's feeling much better in 2007.

"You're never going to be perfect in this game of football," Coston said. "You just have to learn how to play through some stuff. Overall, I feel pretty good about my health.

"I think the healthier you are, the easier it's going to be to raise your level of play, no matter where you're at."

Philbin estimated that Coston missed maybe one morning practice during two-a-days because of soreness in his knee, but otherwise he's been available, as well as willing and capable, of playing wherever the coaches need him.

"Probably one of the laws of nature is that if you're out here and you're working, you're probably going to get better and improve," Philbin said. "That's no accident.

"He's been very, very healthy, and he's worked extremely hard. He's got some fine natural athletic ability as well. You combine all that, ... he's coming along."

{sportsad300}An impressive day

One day after cornerback Jarrett Bush was elevated to the nickel spot with the No. 1 defense, another cornerback stepped forward and had a very strong practice on Tuesday.

Free-agent signee Frank Walker made some impressive plays in pass coverage throughout the workout. During red zone work, he broke up a pass from Brett Favre to Donald Driver, who ran a post route into the end zone. A little later, he intercepted Favre during seven-on-seven drills on a throw to Chris Francies, and then he ran stride-for-stride with James Jones on a deep route to the corner of the end zone and batted away Favre's pass.

"I'm just out there working, trying to get better every day," Walker said. "I just like to practice hard, give everybody a good look, try to get them ready for Sundays, and try to get myself ready for Sundays too."

As for where he stands in the battle for the nickel job, or a roster spot in general, Walker wasn't going to guess.

"All I know is what they tell me, (which) is just keep working, they like what they see," Walker said. "(It's not) who makes the most money, who's the highest draft pick, it's not that situation at all. They're just going to make the best decision for the team."

Big beef

During goal-line work on Tuesday, the Packers used the defensive tackle trio of Corey Williams, Johnny Jolly and Ryan Pickett for one series, and the trio of Colin Cole, Jolly and Pickett for another.

According to the players' listed weights on the team roster, that's either 947 or 949 pounds on the interior of a five-man line to try to stuff the run.

Injury, participation update

Head Coach Mike McCarthy is expecting running back Vernand Morency (knee) to be healthy by the regular-season opener on Sept. 9 against Philadelphia. Whether or not Morency will be able to play in the preseason finale next week at Tennessee has not been determined yet.

"I'm just trying to get out there as soon as possible," said Morency, who injured his knee on the first day of training camp. "That's my timetable.

"It pains me every single day that I'm not out there competing, because it's something I love to do."

Defensive end Kabeer Gbaja-Biamila missed his second straight practice to attend to a personal matter.