Kirk Ferentz isn’t fully disclosing how good his 2011 offensive line could be.

Not yet, at least.

Consider his assessment of the group’s performance at the team’s spring scrimmage — it was more critical than his feedback for any other group.

"We did a pretty good job at holding penalties," the Iowa head football coach said following the spring’s final practice on April 16 at Kinnick Stadium. "They had three or four or five, something like that, and a couple exchange problems."

Indeed, there were some yellow flags. And also true, the line didn’t always appear to function smoothly.

Rest assured, though: The O-line has all the makings to be a strength — if not the strength — for the Hawkeyes this fall. All criticism aside, the 13th-year head coach knows that: "We have the potential to be solid there."

Maybe Ferentz’s high standards stems from his own specific coaching background, which includes work as an offensive-line coach under Hayden Fry from 1981-89 and also under Bill Belichick with the Cleveland Browns. Or it could be the classic coach’s adage of "never settling" and "always getting better."

Either way, there’s plenty to like about this group, primarily its experience.

Left tackle Riley Reiff — the line’s cornerstone — has started 24 games over the past two seasons.

There was even some talk that the redshirt junior-to-be could be heading to the NFL early after a solid 2010 season, but the Parkston, S.D., native has never indicated that he even considered it. One more impressive season, and Reiff could find himself making a trip to Radio City Music Hall for the 2012 NFL draft. Looking ahead, Walterfootball.com projected the 6-6, 300-pounder to be selected 10th overall next April.

At the other end is redshirt senior Markus Zusevics. Zusevics entered 2010 unproven, and emerged as a solid anchor at right tackle after starting all 13 games.

Also starting in each of the Hawkeyes’ games last season was James Ferentz — the coach’s son — at center. He filled the void left by the graduation of Rafael Eubanks, and he should be even sturdier this year. The City High alumnus said a season of in-game experience has accelerated his progression.

"When we watch the tape, you just have a better understanding," he said on April 16. "You can see things a little bit better. You start to see outside of that seven-man box, see safeties a little bit more."

Plagued by injury, Adam Gettis only started two games last season at guard. With four years in the program behind him, though, staying healthy is probably a bigger concern than ability for the redshirt senior.

Then there’s the group’s wild card, Brandon Scherff. Scherff — who played with the No. 1s on offense during the scrimmage — could be the difference between a good line and a great line.

The 6-5, 310-pounder is about as big as underclassmen come. He was nearly 300 pounds coming out of Denison (Iowa) High School, where he was ranked among the top-50 offensive tackles in the 2010 recruiting class by Rivals.com.

Size and athleticism alone aren’t enough for success, though.

"I’ve seen a big guy who can move his feet who’s got to learn what he’s doing," offensive coordinator Ken O’Keefe said about Scherff on April 13.

O’Keefe called the positions along the offensive line most difficult position to learn besides quarterback, and for a player with less than a calendar year in Iowa’s system, that difficulty is compounded. James Ferentz sympathized, recalling the head-spinning moments that he dealt with as a younger player.

"You feel for him, because you want to do it right, you want to be the guy," he said. "But it’s just really difficult as a freshman.

"It’s hard to understand what people are saying. It’s kind of like a foreign language a little bit."

Listening to his peer and coaches’ reviews, though, Scherff’s potential suggests he may be better than adequate when the real games roll around.

"He’s a really smart and talented kid," James Ferentz said. "We all believe in him, and we think that he can get the job done."