Injured linebacker Steve Octavien had an MRI on his hamstring Wednesday afternoon, Nebraska coach Bill Callahan said.

Octavien, who’s missed the Huskers’ last two games, returned to practice Tuesday but was sore Wednesday morning.

“It’s more preventative than anything right now,” Callahan said of the MRI, “just to see where everything’s at, to rule out anything.”

Callahan said Octavien could have practiced Wednesday. Octavien’s status for Saturday’s game at ISU appears unclear.

Also, center Kurt Mann, who’s been recovering from mononucleosis, has practiced the past two days.

“He’s been working hard,” Callahan said. “We monitor his reps so we make sure that he gets what he needs, but we don’t wear him out. We want to prevent any type of relapse.”

Callahan said Mann is “a little bit weak” and admits to getting tired toward the end of practice. He said it’s possible Mann will travel with the team to Iowa State.

“He’s still a ways away,” Callahan said. “We could probably use him in an emergency situation.”

ON GRASS: In preparing for Saturday’s game on the grass field at Jack Trice Stadium in Ames, the Huskers have been working out this week on the grass fields. Most of the work has come on the farthest east of the two new practice fields; Callahan said the field adjacent to Hawks Championship Center is newer and won’t be ready for full use until spring. But he noted the field is improving. “The root system is much deeper,” Callahan said.” It’s about 6 inches, and it’s packed down pretty good. We roll it and it’s getting better. It still tears up now and then, but that’s to be expected, because it’s rather new.”

INTENSITY: When asked how the defense has performed in practice this week, Callahan responded: “It’s been an intense week of practice. We’ve worked on all phases of our game, the pass rush, the run game, the coverage game.” He also stressed the concept of playing team defense. “We’re trying to tie everything together and coordinate everything so we’re complementing each other in all facets,” he said.

SEE IT: It’s common to wonder if coaches hold back some plays during the early portion of the season so upcoming opponents don’t see them on tape. Sometimes, it works the other way. Nebraska quarterback Zac Taylor referred to the three touchdown passes of 75, 78 and 75 yards against Kansas. “That’s good for us to be able to put that on film and have teams be aware of that,” Taylor said. “It scares defenses when they know you scored on three plays of over 70 yards. They’re going to be a little nervous about the double move and things like that.”

DON’T BELIEVE IT: In 16 NCAA statistical categories, the Cyclones rank in the top 50 in only two — they’re seventh in punt returns and 31st in passing offense. They rank 80th or lower in nine categories. Nebraska players aren’t buying it, Taylor said. “You don’t look at what they’re ranked in certain categories,” he said. “You just know they’re going to play their best and it’s going to be a tough contest.”

ETC.: Nebraska hasn’t started conference play 2-0 since 2001. … Nebraska needs two more victories to reach No. 800 all-time. … The Huskers are 11-1 under Bill Callahan when scoring first.