The Packers' starters will play as much as two quarters in Friday's preseason game in Indianapolis, but no more.

Head Coach Mike McCarthy confirmed his plan for playing time on Wednesday, saying he'll assess things midway through the second quarter with an eye toward getting as many snaps as possible for rookies and others fighting for roster spots as the game continues.

"We need more information on our younger players, our newer players," McCarthy said. "I know you traditionally play into the third quarter (in the third preseason game). We will not do that. Our starters will not come out in the second half."

That's OK with quarterback Aaron Rodgers, who pointed out that the last two years the offense has been at its sharpest in the third preseason game and has called it a night at halftime.

"Just need to get our work done, hopefully stay healthy and get out," Rodgers said.

One starter who may not play at all is receiver Greg Jennings, who sat out Thursday's practice with a bruised knee. McCarthy didn't rule him out but he did rule out fellow receiver Randall Cobb, who has bruised knees. McCarthy said he hopes Cobb can return to practice next week.

Also ruled out are defensive end Mike Neal (knee), linebacker Frank Zombo (scapula) and all three players who have sustained concussions – defensive ends C.J. Wilson and Lawrence Guy and safety Anthony Levine.

Linebacker Brad Jones returned to practice on Wednesday from a knee injury and barring a setback is expected to play.

The punt protection and punt rush should be special-teams elements worth watching on Friday based on what's happened in practice lately.

Punt rushers have blocked at least one punt in practice every day this week, with rookie running backs Brandon Saine and Alex Green both doing so on Wednesday. McCarthy attributed the blocks to technique errors by the blockers, which is a bit unsettling, but from the other side it's encouraging for young players to make an impact like that.

"It's good to see a young guy flash that kind of ability, because we haven't had a lot of time with these guys," McCarthy said. "When you see someone new do that, it's definitely a positive."

Rookie receiver Tori Gurley blocked punts on both Monday and Tuesday, and with him it may not be beginner's luck. Gurley's special teams coordinator at South Carolina was Shane Beamer, son of longtime Virginia Tech Coach Frank Beamer, who is renowned for dynamic special teams units that have earned the label "Beamer Ball."

"I worked a lot of one-on-one time with Coach Beamer about using my body and my length to block punts," said Gurley, who's 6-4 and 216 pounds. "It's part of a special-teams niche I have."

Gurley believes his two blocks this week give him four total in camp so far. He said he's never blocked one in a game, but once he did scoop up a fumble by a punter when the rush wrecked his concentration. If Gurley can get his hands on a punt in one of these last two preseason games, that could become a weapon too dangerous to ignore.

"It means a lot, because that's game-changing," he said. "You can put A-Rod in position with a short field, and we're going to score. It's all about takeaways."

As for other young players the coaching staff wants to evaluate further, inside linebacker Cardia Jackson will look to follow up a standout practice on Wednesday with a strong game.

Jackson made three noteworthy plays during team (11-on-11) work. First, while dropping into pass coverage, he snared an Aaron Rodgers bullet intended for receiver James Jones. Later, he deflected a pass over the middle from third-string QB Graham Harrell.

He made perhaps his best play toward the end of practice, deflecting a pass at the line of scrimmage, turning around and catching it for another interception before it hit the ground.

"Actually I was blitzing and the offensive line held me up," Jackson said. "I got my hand up in the air, he threw the ball, and voila, it landed in my hands."

Jackson is trying to earn a roster spot as a backup inside linebacker amongst a reserve group that also includes Robert Francois, rookies D.J. Smith and Elijah Joseph, and K.C. Asiodu, who missed practice Wednesday (chest injury).

A member of the Packers' practice squad during the playoff run last winter after getting cut by the St. Louis Rams following training camp, Jackson is still learning the 3-4 defense, a scheme he never played while leading the Sun Belt Conference in tackles at Louisiana-Monroe. Jackson made all his big plays Wednesday on the scout-team defense.

"I don't look at it like a scout team," he said. "I look at it as I'm the opponent and showing these guys a good look. You go out and make plays against the ones, that's pretty big."

Even bigger would be making an NFL roster, and he can make an even stronger case for himself in Indianapolis on Friday night.

"It's never over until they tell you you're cut," he said. "I know how it feels to be cut, and I don't want that feeling anymore."