As has been the case throughout his tenure in Green Bay, coach Mike McCarthy won’t play his starters much in the Packers’ fourth preseason game.

Thursday’s finale at home against the Kansas City Chiefs will be the final showcase for fringe players trying to earn a roster spot, as well as possibly the last chance for Graham Harrell to prove he deserves the backup quarterback job.

“The starters will play a very limited time in the first quarter,” McCarthy said.

Quarterback Aaron Rodgers, LB Clay Matthews and other entrenched players will do nothing more than make brief cameos against the Chiefs. Since becoming the starter in 2008, Rodgers has never played more than one series in the last preseason game.

It will be interesting to see how many and which first-team offensive players stay on the field to play with Harrell after Rodgers departs. Harrell has struggled so far in the preseason -- completing 50.8 percent of his passes with passer rating of 53.7 -- but he’s played behind a weak offensive line and with less-talented receivers. The No. 2 offense has mustered just two touchdowns in three games, both coming in the opener at San Diego.

There have been calls to let Harrell play with the starters in order to more accurately evaluate his ability -- he’s been victimized by constant pass-rush pressure and wide-receiver drops that distort his bleak statistics. While it’s unlikely that McCarthy will jeopardize the health of his No. 1 offensive line, Harrell is likely to get a chance to play with at least some of Rodgers’ weapons who’ve missed preseason time.

TE Jermichael Finley and WR Greg Jennings could remain in the game with Harrell since Finley hasn’t played a preseason snap yet due to injuries and Jennings only returned from a concussion last week. In addition, RB Cedric Benson, who was signed two weeks ago and is still learning the playbook, could use the extra reps.

Still, to hear McCarthy discuss the possibility, it seems Harrell will have to again go through the fire with the backups.

“We’ve never taken a backup and put him with the number ones,” McCarthy said Tuesday. “You’re evaluating the whole football team. It doesn’t just happen during preseason games. There’s a lot that goes into evaluating players and the quarterback position. I’m more interested in seeing Graham improve in the areas that we feel he needs to improve on, and I’m seeing it.”

For his part, Harrell said he only hoped to play well and wasn’t concerned with trying to prove himself to critics.

“My goal is to just improve,” he said. “That’s what you’re supposed to do.”

On the defensive side of the ball, two important spots remain up for grabs: right cornerback and nickel safety. At cornerback, Jarrett Bush, Sam Shields and Casey Hayward are in the mix and they’ll play more than Tramon Williams in hopes of turning heads and winning the job. At safety, M.D. Jennings, Jerron McMillian and Anthony Levine are competing to be the strong safety when veteran Charles Woodson moves to slot corner in the Packers’ oft-used nickel package. Each of the three players at both positions has had his opportunities with the No. 1 defense, and Thursday is the last chance for any of them to prove they deserve to be starting when the regular season begins.

“This week is really for the young guys,” Rodgers said of the Chiefs game. “We’ve got 75 guys and we have to cut 22 … so a lot of jobs are up for grabs for those guys.”

Follow Packers reporter James Carlton on Twitter: @CBSSportsNFLGB and @jimmycarlton88.