GREEN BAY – First-year quarterback Graham Harrell started to show some of the promise he displayed while he set several NCAA passing records directing a prolific offense at Texas Tech.

In probably his best practice in a Packers uniform, Harrell appeared to show better decision-making and timing on his throws than at any previous point in Green Bay.

Whether it's because of inexperience with his offense and receiving corps or a reluctance to make a mistake, Harrell hadn't previously shown a penchant to push the ball downfield, a stark contrast compared to starter Aaron Rodgers. That changed on Thursday.

One of the better plays of the morning was when Harrell hit rookie tight end Andrew Quarless  while reaching over his back shoulder to make reception with linebacker Robert Francois in close coverage.

Perhaps even more impressive was when wide receiver James Jones beat cornerback D.J. Clark streaking down the center of the field. Flynn floated a perfectly thrown football into Jones' hands, but unfortunately the wide receiver couldn't hang on.

On a day when Harrell seemed to "get it," it just so happened to coincide with a practice that backup quarterback Matt Flynn struggled. The most noticeable mistake was a throw in the left flat picked off by Sam Shields for what would have an interception returned for a touchdown. Other passes broken up by Tramon Williams and A.J. Hawk on passes from Flynn didn't help the No. 2 QB's cause.

Safety first: Safety and return specialist Will Blackmon continued to sit out of this morning's practice, a trend that has now continued for about a week.

"The doctors have been telling me the same thing that I have been repeating right here every day," said head coach Mike McCarthy following practice. "They think his knee, it’s not ready for training camp-type schedule. We try to keep him on one-a-days. I know he wants to go. I know Will is frustrated. He wants to get out here and go, but Dr. McKenzie thinks he is going to be fine once he gets through this period."

That begs the question, why was Blackmon allowed to practice the first week of training camp? He apparently hasn't been ready for a regular season, one-a-day type of schedule either. McCarthy wasn't asked to elaborate.

First preseason game: Based upon McCarthy's comments, Aaron Rodgers and the first-string offense will play a couple series in the preseason opener when the Packers host the Cleveland Browns on Saturday at 7 p.m.

"Probably close to 20 plays," said McCarthy. "Somewhere in there with the first group. That’s my thought today. But we have a practice tonight. Tonight’s practice will answer most of our questions on how long we’ll play the first group Saturday night."

Rodgers will likely play close to one quarter of football, but it's tough to say whether McCarthy will change his mind based either upon tonight's practice or how well the offense performs.

If the "ones" put together a sustained drive on their first possession that ends in a touchdown, McCarthy may be inclined to pull them so as not to subject them to possible injury.

Punting plan: McCarthy said he hasn't yet determined how he plans to use the punters although he indicated he's considering a couple possibilities.

"As far as their holding responsibilities, we’ll probably flip a coin, to be honest with you," said McCarthy. "I just want one holder per game. Now, whether we go every other punt or every two punts, we’ll determine that in the next day or so. I want to make it as 50-50 as I possibly can."