T.J. Lang will get his chance to start at left guard in Friday night’s preseason game against Arizona. He wants to make it a regular occurrence.

Lang and first-round draft pick Derek Sherrod have been competing for the starting job at left guard since training camp opened, and the two have been flip-flopping back and forth between left guard and left tackle on almost a play-by-play basis in practice as veteran left tackle Chad Clifton plays limited snaps.

The versatility of both linemen will come in handy in the long run, and it never hurts to have multiple bodies capable of playing the all-important left tackle spot.

Left guard is the only starting job open on the offensive line, however, and after Sherrod started the preseason opener in Cleveland, now it’s Lang’s turn. Head Coach Mike McCarthy confirmed on Thursday that Lang would start.

“If I can lock up that spot, it’s something I don’t plan on giving up for a while,” Lang said. “I’m excited.”

Lang, a fourth-round draft pick in 2009, has never started at guard. His three starts as a rookie came at the two tackle spots as an injury replacement for Clifton and Mark Tauscher. His development was slowed last year due to offseason wrist surgery, and he never really competed for a starting spot as expected.

He said on Thursday that his No. 1 goal this summer was to nail down a starting job. If the coaching staff wants to have its offensive line in place by the third preseason game – the one in which the starters usually play the most – then Friday night is Lang’s opportunity to step forward.

“It’s still a competition,” Lang said. “I’m sure nothing’s set in stone, yet. We’re both going to get plenty of looks, Derek and I, and I’m going to go out there and play the best I can and hopefully try to make it a clear decision for the coaches.”

McCarthy ruled five players out of Friday’s game due to injury – defensive lineman Lawrence Guy (concussion), safety Anthony Levine (concussion), guard Adrian Battles (Achilles), tackle Chris Campbell (shoulder) and defensive back Brandon Underwood (knee).

A handful of others will be evaluated on Friday, among them outside linebacker Clay Matthews, who sat out Thursday’s abbreviated practice with tightness in his hamstring.

Matthews has experienced hamstring trouble in the preseason in each of his first two seasons in the NFL, and McCarthy said no one is taking any chances.

“I’d say this year is better than the last two years,” McCarthy said, referring to Matthews’ hamstring issues. “He’s definitely aware of it. He’s very conscientious with all his training. We’re always going to play the high side of caution with his history.”

If Matthews rests on Friday, that could mean additional snaps for the three outside linebackers vying for the starting job opposite him. Erik Walden has done the most work with the first-team defense this week, with last week’s starter, Frank Zombo, and former starter Brad Jones also expected to play.

McCarthy corrected the injury information on defensive end Mike Neal, noting he did have an MRI on his injured knee. He declined to discuss the results, but he still lists Neal in the “day-to-day” category. The same goes for running back James Starks (ankle). Receiver Brett Swain (hamstring) went through stretching to open practice on Thursday for the first time all week but then did not run any routes during team drills.

Rookie running back Alex Green, a third-round pick who missed the preseason opener with a quad injury, is expected to make his debut on Friday. McCarthy said Green’s first duty would be on special teams, and then he’d try to work him into the rotation at running back as the game wears on.

“You just want him to stay healthy and show what he’s been showing in practice,” McCarthy said. “He’s a dynamic individual.

“He’s done a very good job in pass-protection, particularly for a first-year guy. That’s usually the area that running backs struggle with the most because, from an assignment standpoint, that’s their biggest challenge. He seems to pick that up, and it comes natural to him.”

The Packers ended Thursday’s practice with a gesture of fan appreciation, tossing T-shirts both by hand and via slingshots into the Ray Nitschke Field bleachers. Some players tossed T-shirts over the fence on the north side of the field to the fans gathered there as well.

“We just wanted to give back and have some fun,” McCarthy said. “It’s great to practice in that environment every day. Our fans are the best.”

The efforts with the slingshots got a bit comical, with some attempts barely trickling forward. All the T-shirts eventually made it into fans’ hands, though.

“We couldn’t figure it out,” said defensive lineman Ryan Pickett, laughing about the slingshot apparatus. “We were trying. We’re all smart guys, we went to college, but we couldn’t figure it out.”

The exercise ended with the players engaging in water-balloon fights, chasing one another around Nitschke Field and attempting to douse unsuspecting teammates and coaches from behind. Afterward, players said they had some extra energy because they were moving out of the St. Norbert College dormitories on Thursday.

McCarthy, who called this past week the most challenging of camp, was asked if he was hit by any water balloons.

“I was in charge of the drill, but I did not get drilled,” he said.