RB Brandon Jackson runs the gauntlet during the opening training camp practice on Monday morning.

With Ryan Grant's contract situation unresolved, the Packers opened training camp on Monday shorthanded at running back for the second straight year.

But the position is far more fortified than it was a year ago.

Last year, when Vernand Morency went down with a knee injury in the first practice, the workload was suddenly turned over to rookie Brandon Jackson, who was backed up by third-down back Noah Herron and another rookie, DeShawn Wynn, who was having injury problems of his own.

Jackson was forced to take a lion's share of the snaps throughout training camp, and it was admittedly too much for a rookie back. Less than a month into the regular season, he was slowed by injuries, before recovering and coming on strong late in the year.

Fast forward to this summer, and without Grant in camp (GM Ted Thompson said Monday both sides are continuing to work on a deal), the first-team reps are once again going to Jackson. But not only is he more prepared, physically and mentally, to handle it, behind him are Herron, a healthy Wynn and Morency, and non-drafted free agent Kregg Lumpkin, all of whom took their share of handoffs on the first day of training camp.

"I think he looks like a different player from this time last year, and I think you could say that for a lot of rookies," Head Coach Mike McCarthy said of Jackson, a second-round draft pick out of Nebraska last year. "I think Brandon Jackson is one of the players as we went through the offseason program that you would expect to have an impact on our season."

McCarthy has repeatedly praised the work Jackson put in during the offseason to improve his strength and build his body. He's listed at 5-foot-10, 220 pounds, eight pounds above his listed weight a year ago.

Toward the end of last season, Jackson also worked his way up to being a core member on special teams, which he had never played regularly before. So the coaching staff is undoubtedly looking for contributions from Jackson in multiple areas, including catching the ball out of the backfield, which he continues to be very adept at.

Grant's absence also gives the other reserve backs fighting for roster spots an opportunity to shine. A lot of workouts and at least a couple of preseason games will be needed before a pecking order can be established, but the experience factor is similar for all of them, except Lumpkin.

Neither Morency nor Herron appears limited by the knee injuries sustained last year, while Wynn is another second-year back looking to make that quantum leap from an up-and-down rookie season. His four rushing touchdowns last season, before going on injured reserve with a shoulder injury, were second to Grant's eight, and his 203 yards were right behind Jackson's 267.

"I think he's done an exemplary job in the weight room," McCarthy said of Wynn. "Very powerful, gifted young man. He's another one I look forward to step up and take advantage of the opportunity he's going to be given."

Men in the middle

McCarthy said defensive tackle Johnny Jolly's reps would be limited coming off last year's shoulder injury, but the third-year pro was thrilled to get back on the field Monday.

With Justin Harrell (back, week-to-week) and Ryan Pickett (hamstring, day-to-day) sitting out practice, Jolly and Colin Cole were the starting defensive tackles with the No. 1 unit on Monday.

"I was waiting to get back to this day right here," said Jolly, who began last season as a starter. "I'm back now. I had fun today."

The shoulder injury ended Jolly's season last November, and then three weeks ago he was arrested in Houston for possession of codeine. He declined to discuss his legal issue, but as far as the shoulder goes, he said he feels 100 percent and could play a game right now if needed.

"I'm focused on football right now," Jolly said. "I'm just looking forward to the season."

Harrell would like to say the same, but the 2007 first-round draft pick is still rehabbing a back injury sustained while lifting weights in the offseason. After missing all the on-field work in OTAs and mini-camps as a rookie due to a torn bicep muscle from his college days, and missing that on-field work again this year, Harrell knows he has a tough hill to climb to get himself up to speed and ready when he's healthy.

But he's determined to do that, no matter how frustrating things are now.

"It's getting close to the season, so whenever they do (give medical clearance), I know I'm going to have to work that much harder to get ready," he said.

{sportsad300}Depth chart

On opening day, Daryn Colledge worked with the No. 1 offense at left guard, while Brady Poppinga was on the No. 1 defense at strong-side linebacker. Guard Allen Barbre and linebacker Brandon Chillar were with the No. 2 units.

At safety, Nick Collins and Atari Bigby handled the reps with the 1's, while Tramon Williams was the primary nickel cornerback during the evening workout.

Second-year pro Desmond Bishop worked as the middle linebacker with the No. 2 defense, ahead of third-year man Abdul Hodge.

Injury/participation update

In addition to Pickett and Harrell, defensive end Kabeer Gbaja-Biamila sat out the morning practice, though McCarthy characterized it more as a veteran getting rest on a day with two workouts than anything having to do with KGB's arthroscopic knee surgery from a few months ago. Gbaja-Biamila returned for the full-padded evening workout.

Left tackle Chad Clifton also sat out a large portion of the morning practice, with third-year tackle Tony Moll taking most of the reps in his place with the No. 1 offense. Clifton returned in the evening for a larger portion of the duty, though Moll did spell him on a few snaps then, too.

Cornerback Tramon Williams dropped out late in the evening practice with what McCarthy called a hip flexor. The extent of the injury was not immediately known.

Among other players who missed time during offseason workouts, Cole (forearm) and cornerback Will Blackmon (foot) did not appear limited in practice. Blackmon also took a few reps returning punts during the special teams periods.