It’s just a five-minute period during practice, and the action may look rather mundane at first glance, but the competitive juices are beginning to overflow now that the Packers are nearly two full weeks into training camp.

During that five minutes, the offensive and defensive linemen and backs execute “half line” runs near the center of Ray Nitschke Field, while the receivers and defensive backs head to the north end for their one-on-ones.

The work is quick, and it’s serious, and that was the case again Wednesday night.

During “half line,” the linemen and tight ends are split into two camps to work on running plays. The left guards and left tackles practice those that go to their side, ditto for the right guards and right tackles. The defenders ready themselves for what’s coming, and the collisions can be pretty fierce.

“You know it’s a run play, and you know it’s going to go through that gap, so you have to man up,” defensive end C.J. Wilson said. “Can he block me and keep me out of the gap? Both sides know where it’s going, and it’s all about manning up, working on your technique and fighting.”

It’s a drill that’s designed to help both sides of the ball get a feel for their run fits, but it’s also a drill that can find the tough guys. The younger the player and the greater longshot he is to make the roster, sometimes the tougher he goes at it.

On Wednesday, two undrafted rookies, fullback Jon Hoese and linebacker Elijah Joseph, met in the hole ahead of James Starks, and the impact was palpable. On Monday night inside the Don Hutson Center, there were two other rookies involved in a similar encounter, as running back Brandon Saine carried the ball right into linebacker D.J. Smith.

“We get after it,” offensive lineman Evan Dietrich-Smith said of the drill, which is run almost nightly during camp. “You set the tempo up there for what you’re bringing into the next periods.”

The offensive linemen don’t like the advantage the defensive linemen have in knowing that it’s a run, and where it’s going, but that forces their blocks to be that much sharper.

“Our fundamentals have got to be right, our steps have got to be right, and we’ve got to be low,” center/guard Nick McDonald said. “So it definitely helps us.”

The advantage switches to the offense when the receivers and cornerbacks go one-on-one. The only other player involved is a quarterback, but there’s no pass-rush and no time clock.

It’s up to the receiver to get open, and it’s up to the defensive back to stick with him, plain and simple. Sometimes the jams and chucks at the line can get pretty rough, and the downfield grabbing and shoving can draw flags, too.

“Nobody wants to falter, nobody wants to fail,” said receiver Chastin West, whose turn on Wednesday night against cornerback Josh Gordy got so physical downfield that West ended up spraining his ankle and dropping out of practice.

“It’s just like anything, you’re going to compete against someone else just because you don’t want to lose. You’ve got 90 guys with big-time competitive spirit, and you put one versus one, put the green light on them, it’s who’s going to win? Make each other look silly. That’s what it is.”

The Nitschke Field crowds always cheer when a receiver wins on a deep route and hauls in a long pass. That’s to be expected, say the corners. They know sometimes they’ve hung with their man long enough that they did their job anyway.

On Wednesday, second-round draft pick Randall Cobb was getting all the cheers on a couple of deep receptions, one of them over cornerback Pat Lee. Receiver Jordy Nelson made a seemingly impossible-to-defend double-stop move along the sideline on cornerback Sam Shields and came back for the catch.

“It’s all timing,” Lee said. “Sometimes it might be a longer play and, in one-on-ones, the quarterback doesn’t have anybody in his face, and we have to be able to stay with it.

“It’s hard. They’ve got that whole field to work with.”

They’ve all, maybe, been doing these drills a little too long now. As important as they are for the focus on fundamentals and how they carry over into the team (11-on-11) periods, Head Coach Mike McCarthy said after practice on Wednesday that he could see the competitiveness getting in the way of clean drill execution.

“It’s the same every year when you get to this point in camp,” McCarthy said. “They’re tired of competing against each other. They’re irritated competing against each other.

“It’s time to go play some live football.”

Saturday, Cleveland; it’s almost here.

Other notes from Wednesday night’s workout:

  • Tight end Jermichael Finley sat out with a “glute contusion,” which could keep him out of the Cleveland game if he doesn’t practice on Thursday. Finley’s absence meant a lot of snaps with the first team for Andrew Quarless, who bounced back from a bad drop along the sideline during an early team period. Quarterback Aaron Rodgers came right back to him on the next snap and Quarless made a diving catch over the middle. Later, during red-zone work, Rodgers hit Quarless on a corner route for a TD.

  • Kicker Mason Crosby is still dealing with his ankle injury, but McCarthy said he’s scheduled to perform a full kicking session in practice on Thursday.

  • In addition to West, rookie defensive end Chris Donaldson also dropped out of practice. The shoulder problem that kept him out of the first week of camp resurfaced.

  • Four of the team’s 2011 draft picks were on the No. 1 kickoff return team – tight ends D.J. Williams and Ryan Taylor, plus Smith and return man Alex Green. Cobb was the other option at return man, and he took over when Green mishandled the first rep from the Jugs machine. Smith was the only draft pick also on the No. 1 kickoff-coverage team.

  • The rotation at the outside linebacker spot opposite Clay Matthews continues. Brad Jones ran with the 1’s on Wednesday. Another outside linebacker, rookie sixth-round draft pick Ricky Elmore, made his first big play of camp when he intercepted a screen pass that was intended for Starks but got deflected at the line.

  • The biggest defensive play of the night was turned in by Shields, who picked off an underthrown deep ball by Rodgers that was intended for Nelson at the goal line. Cornerback Tramon Williams also had a couple of impressive pass break-ups on deep throws, one against Greg Jennings and the other against James Jones on the final play of the first team’s two-minute drill.

  • For the second straight night, third-string quarterback Graham Harrell got the offense to the brink of scoring in the two-minute drill, only to be denied. On Wednesday, a clutch throw over the middle to Taylor converted a fourth-and-long and put the ball in the red zone. Harrell eventually faced fourth down from the 6-yard line with five seconds left, but Taylor was looking the other way on a quick toss and it was incomplete.