LINCOLN — Energy has yet to be a problem for Nebraska through 13 fall practices. But coach Scott Frost said Friday the Huskers' game savvy has been less than reliable.

The team conducted various situational scrimmages inside Memorial Stadium with Big Ten referees officiating. And while enthusiasm was abundant, Frost said his players need to be aware of the specific circumstances of the play while moving at a high tempo.

He offered an example where one team in the lead was trying to run out the clock while the other side had timeouts. But the offense stopped the clock by letting the ball run out of bounds. When the other squad got the ball, it didn't have enough urgency in its two-minute drive.

"We need to have a smart team, not just a talented team," Frost said. "And I think we have a lot to learn from today."

Penalties also cropped up too often. Big Ten officials — not the usual refs Nebraska brings in from local high schools or small colleges — gave the Huskers a better taste of how disciplined they'll need to be in a few weeks.

"Some of the little things that you kind of gloss over in practice are going to get called by a Big Ten crew," Frost said. "So it's going to be great film for us to watch that and make sure that we're detailing our technique so those things don't happen."

Young players rise, Green impresses

Frost joked that he's never adjusted a practice for one player before. But he did tweak a few things Friday so Nebraska could get a better look at its newest arrival.

Junior college transfer Jahkeem Green — the defensive lineman who partook in his first practice Wednesday — is still not able to practice in full pads by NCAA rule. So the last 10-15% of the situational scrimmage Friday was scaled back to accommodate the lineman who was in "shells" only.

"We got him some reps. He's obviously a talented kid," Frost said. "He's got some work to do to get into the type of condition the other guys are in. But you can definitely, just today, see some flashes of what he can do."

The scrimmage was without many of Nebraska's skill players. Frost said 10-12 of NU's best players didn't take reps with an eye toward keeping them healthy. A "bunch" more saw limited action. Among those absent were receivers Kade Warner, Wan'Dale Robinson, JD Spielman and Kanawai Noa.

"We had quite a few receivers that weren't out there today," Frost said. "That gave a lot of the young guys a chance to get some reps and some of them took advantage of them."

One was redshirt freshman Miles Jones, who is healthy after missing most of last year recovering from shoulder surgery.

Quarterback Adrian Martinez was "limited" but took snaps in a four-minute and two-minute situation, along with a red-zone possession. One series, Frost said, backed up into the offense's own end zone.

"He made some good plays," Frost said. "I think there's a couple lessons he can learn too. But he's had a great camp. He's markedly better than he was a year ago at this time."

High on backup QBs

Frost remains bullish on the Huskers’ backup quarterbacks.

For a second straight week, Frost praised the work of the four signal callers battling for the No. 2 spot behind Martinez. Wahoo Neumann graduate Noah Vedral — who followed Frost from Central Florida to Nebraska — is playing as well as Frost has seen him play.

“He’s doing some amazing things,” Frost said of Vedral, who shook off rust last season and turned in a strong spring game performance.

Andrew Bunch, who started a game last season, has improved. Frost said the same of Matt Masker, the redshirt freshman walk-on who graduated Kearney Catholic.

The talk of camp — true freshman Luke McCaffrey — had another strong day.

“McCaffrey’s understanding of the offense is elite, honestly, for his age,” Frost said. “I think he’s faster than I expected him to be and he throws it really well. He’s also got that knack to make plays when stuff breaks down with his feet and his arm. A little bit of the magic that we want our quarterbacks to have so something can be created even when nothing’s there.”

Quick hits

» Frost said NU is starting to see the benefits of the walk-on program. He specifically named offensive guard Trent Hixson, running back Wyatt Mazour and inside linebacker Luke Reimer.

"We're starting to not just get depth from the walk-on program," Frost said. "We're starting to be able to identify some guys that can be guys to help us win games and potentially be starters for us."

» Nebraska will go three or four more practices before defining roles in greater detail ahead of the Aug. 31 season opener. That includes specific roles on offense and defense and who will be on the scout team.

» Specials teams improvement should be an "easy step," Frost said, because there are more athletes on the roster. He said the punter battle between left-footers Isaac Armstrong and William Pryzstup is looking good and will continue.

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