Twenty yards on 23 carries — 0.87 yards per attempt.

That was the Iowa rushing game against Penn State. The Hawkeyes collected 50 yards on 13 positive carries, then erased more than half the progress with 8 negative attempts for a loss of 30 yards.

The Hawkeyes ran for negative net gain in both the second and fourth quarters, rushing for minus-15 yards and minus-2 yards, respectively.

Those are a lot of numbers used to say one simple thing: Iowa didn’t have a running game against the Nittany Lions. It wasn’t just ineffective, it was nonexistent.

There were several reasons for that failure: Left tackle Brandon Scherff and right guard Andrew Donnal suffered injuries early in the second quarter, and Iowa powerhouse tailback Mark Weisman was only “around 80 percent” recovered from a week-old sprained ankle.

Weisman wasn’t listed on the depth chart all week, but he tried to play anyway during the first half.

The sophomore took two first-quarter carries for 8 yards, but slowed when his ankle started to bother him.

Weisman rushed three times in the second quarter — twice for no gain and once for 1 yard. His ankle limited him and finally shut him down for the rest of the game.

But that’s no excuse, Weisman said.

“I wasn’t really being effective out there,” he said. “So that’s hurting the team more than helping it.”

He had been a question mark all week, Vandenberg said, so the rest of the offense should have been ready to support Greg Garmon as its primary runner.

“We weren’t really sure what we were going to get [from Weisman], and if it bothered him at all, he wasn’t going to stay in there,” Vandenberg said. “Rather be safe than sorry.”

The Penn State defense was physical, but Iowa center James Ferentz said the offensive line didn’t do its job, either.

“They’re a really physical defense … but that falls on the offensive line,” Ferentz said. “We need to do a better job of getting bodies on bodies, and we weren’t doing that consistently. That makes it really hard for a young back.”

Ferentz said the injuries to Scherff and Donnal didn’t have “anything to do with” the ineffective running game. The Hawkeyes started the contest coming out of the tunnel — escorted by fireworks and a striped stadium full of rally towels — and went three and out. On third and 2, Garmon was stuffed short of a first down.

“We come into an environment like this — Kinnick is second to none, and the fans were ready to go — and we don’t give them anything to get fired up about,” the center said. “It wouldn’t have taken much, but we came out and did the worst thing possible … That starts with me at the center position and the offensive line.”

Ferentz said it came down to an issue of fundamentals and drive. The Nittany Lion defense played the best it has all year, defensive tackle Jordan Hill said. Iowa didn’t, and that’s why the Black and Gold ran for less than 10 percent of the yards Penn State gained.

“When you face a defense that’s outplaying you, and they’re a little bit hungrier, it makes it very difficult to execute those very simple, fundamental plays,” Ferentz said. “But at the same time, we need to come out with some more fire there. For whatever reason, we didn’t have it tonight, and they did.”