GREEN BAY, Wis. -- Aaron Rodgers finished Tuesday's practice by running the scout team -- a sure sign he won't play in Thursday's preseason opener against the Tennessee Titans -- and he wasn't happy about the way it went. He grew so frustrated that on the final play of the drill, he flung the ball toward a couple of tackling dummies on the sideline.

No, it wasn't that Rodgers loathed the assignment of scout-team reps.

In fact, it was just the opposite.

His frustration stemmed from the fact that the young players -- most likely the young receivers -- didn't seem to be giving the drill the effort it deserved. The task is seemingly simple: read the card that shows the play the coaches want run in order to give the No. 1 defense the look it will see from the Titans.

"It was one of the worst cards sessions we've had," Rodgers said. "I don't know how you can make it any simpler. You literally have what the play would be in our terminology on the card, and the effort level was very low, especially with what I'm accustomed to. I've been running that period for a number of years. So it's not a good start for us on the card period for the young guys. I think [DeAngelo] Yancey has really progressed, G-Mo [Geronimo Allison]. Obviously, 16 [Jake Kumerow]. But everybody else was kind of piss poor."

Welcome to the NFL, Rodgers style.

When asked if he was trying to send a message, Rodgers said: "I was just answering the question. I think it's pretty evident to anybody watching the end of practice, there were some mental errors. That's the frustrating thing. It's one thing if you're picturing a play in your mind and you're thinking about it and you're a little off, but when you're looking at a card that tells you exactly where to line up and exactly where the play is, there aren't any excuses for that."

The Packers drafted three receivers -- J'Mon Moore (fourth round), Marquez Valdes-Scantling (fifth round) and Equanimeous St. Brown (sixth) -- yet Rodgers has repeatedly praised Kumerow, a former practice-squad player. There has been a heavy focus on the young receivers, especially given the fact that the Packers cut veteran Jordy Nelson in the offseason.

"I'm getting older and grumpier. I've been at this for a long time. I'm tired, too; we're all a little tired. When you get a little tired, the fuse gets a little shorter."

"I was telling Jake the other day, I watched a play that he was in on, he ran a certain route, he was open on the route. I wasn't the quarterback, we came back three practices later, same call, same coverage, same player -- him -- running the route, and he wasn't expecting the ball," Rodgers said. "I said, 'Hey, I watched that rep three days ago. I saw this play and I reminded myself at the time, if we had that opportunity again, where to go with the football.' I said, 'When you're out there, I'm coming your way.' I have confidence in him. He's in the right spot all the time, he makes contested catches, finishes the right way. He practices like a pro.

"It's a reminder to those other guys, this is what it looks like. 17 [Davante Adams], that's what it looks like; 18 [Randall Cobb], that's what it looks like; 81 [Allison], that's what it looks like; 80 [Jimmy Graham], that's what it looks like; 84 [Lance Kendricks]; 89 [Marcedes Lewis]. Those guys are practicing like pros. That's how you stick around in this league. It's not some of the stuff we've been seeing through practice, and it's repeat mistakes."

Rodgers typically highlights players who stand out, but rarely does he express the kind of disappointment that he showed Tuesday.

"I'm getting older and grumpier," Rodgers said. "I've been at this for a long time. I'm tired, too; we're all a little tired. When you get a little tired, the fuse gets a little shorter. Again, you're in like the 14th play of a 14-play drive and you've got low effort level and an MA [missed assignment], that's a little frustrating."

Said veteran receiver Adams: "I don't think it was necessarily today that made him to where he wanted to say that. I think it's an accumulation over time -- people having to be told the same thing more than once. That could have definitely factored in."

A dejected Moore sat in his locker after practice, and when told of Rodgers' comments said he understood his quarterback's frustration.

"There's specific ways they want it run; they hold the card up there for a brief amount of time, and then that's it," Moore said. "Today was our first time doing it. It happens fast. So it was just something that you have to get used to. It gets easier the more you do it. But at this level, you've just got to get it. They're going to throw you out there and they expect you to have it, and it's something that you've got to develop and be able to just do it."