Saturday's opening training camp practice at Ray Nitschke Field featured the return of several players returning from significant time missed, including guard/center Jason Spitz (back), defensive end Justin Harrell (back), wide receiver Brett Swain (knee), cornerback/returner Will Blackmon (knee) and tackle/guard T.J. Lang (wrist).

Spitz, who started four games in '09, two each at center and left guard, underwent season-ending surgery on his back in November. On Saturday he worked at all three interior spots in with the second line, with the first group comprised of Daryn Colledge at left guard, Scott Wells at center, and Josh Sitton at right guard.

"It's one of those things where we have so many guys now that you have to kind of mix and match and put guys where they should be and get the best fit for the team," Spitz said. "I kind of had a feeling that I could be almost anywhere coming back. We've got a lot of good players in that room and I'm just glad to be in there and just get a chance to work again."

Head Coach Mike McCarthy said that how reps are distributed at the interior-line positions during camp will be a "day-by-day" process, and Spitz's focus is centering on showing the coaches he can be the same player that has started 45 games during his four-year career.

"I think today and early on it is going to be see what I can do, where I can do it, and then just wherever I can fit in and help out is where I am going to be," Spitz said. "Honestly you can say obviously I want to be a starter, but I've got to get back to playing the way I was playing before I got hurt."

Harrell has been limited to just six games over the past two seasons due to back problems, which forced him to miss all of 2009, but he has cleared all of the hurdles during the offseason. Last year he reinjured his back in the opening week of training camp, so the focus for him is staying healthy now that the pads are on.

"We kind of made a checklist," Harrell said. "We made it through mini-camp, OTAs, and now we are here in training camp. It's just another step. Hopefully things just continue going good and just continue to work."

Blackmon tore his ACL in Week 4 on a kickoff return at Minnesota last season, and is not only returning from injury but also working at a new position as he makes the switch from cornerback to safety. He is also expected to compete for the punt and kick return jobs.

"I am aware that it is probably going to be sore here and there every once in a while, but other than that, between the whistles I am just out there playing full out and not even worrying about it," Blackmon said.

Lang, who started games at both tackle spots as a rookie, wore a brace in practice to support his wrist and worked on the right side.

"I felt a little rusty with my technique," Lang said. "Also, I was playing a little right guard and right tackle and I had to change my technique up a little bit. I was kind of favoring the wrist a little bit, even though it wasn't really bothering me. Just having the brace on it was in the back of my head.

"I still need to get better and still need to improve. But I am just glad to be back on the field running around and playing with the guys."

Ready to go
McCarthy said on Friday that defensive end Ryan Pickett reported to camp in the best shape of his Green Bay tenure, which the veteran lineman said was partially attributed to his switch in positions.

Pickett anchored Green Bay's No. 1-ranked run defense at nose tackle in 2009 but worked at left end this offseason due to the absence of Johnny Jolly, who was suspended indefinitely by the league for violating the NFL's substance-abuse policy.

"I'm in pretty good shape, yeah, I must say probably than I have been coming into camp," said Pickett, whose listed weight is 340. "I took the switch seriously. I wanted to be a little lighter, move a little better at end than I was at nose.

"(The team) didn't really tell me to (lose weight). I took it on on my own. They told me to be at a weight, but I wanted to be a little lighter."

Pickett said the responsibilities for an end compared to nose tackle in defensive coordinator Dom Capers' scheme will take some getting used to.

"It's not like you are really firing off at all, getting up field, so it is a lot of reading inside, lateral movement, things like that," Pickett said. "Sometimes at nose I could just get off the ball, but at end it is a little different.

"I have never played a 3-4 end but last year I had never played nose tackle. So I adjusted to it and I am adjusting now. I don't have it down. I have to keep going and learning. The more reps I do, the better I'll be at it."

More tests for Bigby
McCarthy said the team will do further testing on safety Atari Bigby's injured ankle before determining when he will be able to return to the practice field.

Bigby was placed on the physically unable to perform list Friday after failing his physical due to the injury that originally dates back to the 2008 preseason. He was not a participant in the Packers' offseason program, instead working out on his own as an unsigned restricted free agent, and said the ankle did not bother him this offseason until it flared up on Friday.

"I was surprised," Bigby said. "I went through my run test, got through it, felt a little shaky about it, but I ran and I was in shape. I came here in shape."

Bigby, who signed his tender in order to report to camp on time, remains hopeful that a contract extension can still be worked out with the team.

"Now I am just focusing on playing football, getting back healthy, getting back out there," Bigby said. "I'll let my agent and Ted Thompson work out all of those decisions."

Injury/participation update
The only players that missed Saturday's practice were the three players on the physically unable to perform list, with Bigby, cornerback Al Harris (knee) and running back James Starks (hamstring) sidelined.

Brad Jones, who worked with the No. 1 defense at left outside linebacker early in practice, took a helmet to the back and dropped out of practice. Veteran Brady Poppinga took the first-team reps in Jones' absence.

"I stepped out of practice to be safe, and I think that was the best decision and what to do," Jones said. "There are no pads right there. It happens."