GREEN BAY – Once the season ended, Josh Sitton already had a roadmap in place for how the Packers' left guard wanted to attack his offseason.

Sitton, entering his ninth year in the NFL, had his mind set on dropping around 20 pounds before the team returned for the start of the offseason program on April 18.

It didn't come at the advice of any teammates or coaches. Sitton decided on his own that he needed to make a few changes to his diet with his 30th birthday on the horizon.

"It's easy to play at 325, 330 when you're 22, 23 years old," Sitton said. "It's a little bit harder when you're coming on 30. It kind of helps with everything. I usually lose a few pounds during the offseason every year. This year, I did a little bit more."

It's not like Sitton was coming off a down year. He had just been selected to his third Pro Bowl and named to the All-Pro second team for the third consecutive season.

Sitton's reasoning had more to do with the discomfort he was dealing with during the season's weekly grind. He's started 79 consecutive games dating back to 2011, but was often limited in practice during the latter half of the year due to persistent back pain.

The way Sitton looked at it, the less weight he was carrying during the offseason, the better it would be for his back and joints in the long term. He planned to shed some fat and gradually put on good weight in time for the 2016 season.

He didn't make any drastic changes to his offseason training, but simply ate cleaner during his time off.

Sitton said he weighed between 325 and 330 pounds at season's end. Right now, he estimates he's in the 305-to-310 range, which is the lightest he's been since 2011.

Offensive line coach James Campen was somewhat startled when he saw Sitton for the first time this spring. That's when Sitton revealed his other motivation for the makeover.

"He goes, 'Yeah, I need to practice more,'" Campen recalled. "I mean shoot, that tells you a lot about a person because he understands the value of practice; the fact that he wasn't able to practice as much as he usually would because of the aches and the pains and all this stuff, it tells you something."

Campen wasn't the only one who came away impressed with Sitton's offseason.

"He looks pretty svelte, doesn't he?" QB Aaron Rodgers said. "He looks great. I'm happy for him. He's in a contract year, so he came back looking really good. He's also getting married, so you want to look good in those wedding pictures, too."

Sitton said he's moving well and even felt a bit quicker during the first week of organized team activities. He didn't appear to be limited at all during Tuesday's public practice.

Unlike other skill positions, Sitton believes this time of year is imperative for offensive linemen who can't really simulate line movements at off-site facilities.

The best way for players in the trenches to prepare for an upcoming season is to be in-house, working with their coaches and fellow linemen. Now in the third and final phase of the offseason program, he's concentrating on different pass sets and hand placement.

"The first week out there, you kind of feel like a newborn deer almost," Sitton said. "Your legs are a little wobbly because you can't imitate those movements no matter what training you're doing. You can at receiver and quarterback, but as an offensive linemen, you can't really imitate that."

The Packers are in a unique position of returning all nine offensive linemen they carried on the active roster last season, along with two rookies (Indiana's Jason Spriggs and Stanford's Kyle Murphy) who were added in the NFL Draft.

New blood doesn't bother Sitton. He understands the need for added depth after the litany of injuries that the starting line weathered this past season. Sitton's only concern is on putting together another Pro Bowl-caliber year.

There's still two months until training camp, but the Packers' longest-tenured lineman is off to a good start.

"It's a tribute to him understanding where his body is at in this stage of his career," Campen said. "I think it shows professionalism. The ability in the offseason not to just go and drink a bunch of pops and eat a bunch of cheeseburgers. Really, you're dedicating yourself to your career. He looks terrific."