A number of things factor into run production and the only thing missing this year — as Stanford prepares for its season opener Saturday against Sacramento State at 3:30 p.m. — is a back with Heisman Trophy-type credentials.
The offensive line returns four of five starters and fifth-year senior Derek Hall won the battle with an experienced James McGillicuddy for the other starting job. Andrew Phillips, Chase Beeler, Jonathan Martin and David DeCastro opened holes for Gerhart.
There will be a new starting tight end, but plenty of experience in Coby Fleener and Konrad Reuland. Redshirt freshman Levin Toilolo, a 6-foot-8 talent, has beaten out both returners.
Senior Jeremy Stewart, sophomores Stepfan Taylor and Tyler Gaffney plus redshirt freshman Usua Amanam may not have 'Heisman Trophy candidate' written all over them, but they are serviceable backs. They have 948 career rushing yards among them.
Perhaps the biggest factor, though, is senior fullback Owen Marecic, maybe the best blocking fullback in the nation. How much of a toll playing linebacker will take on him is open for discussion, but there's no questioning his abilities to ignite the running game without ever touching the ball.
His offensive stats are so misleading you'd think he didn't know what a football looked like. A three-year starter at fullback, he has gained just 21 career yards on 13 carries.
Marecic's real offensive stats, however, are contained in numbers like 3,522 and 44. Those are Gerhart's career rushing yards and career touchdowns with the Cardinal.
It doesn't stop there. Anthony Kimble enjoyed a career year running behind Marecic, gaining 717 yards and scoring six touchdowns in 2008. Kimble gained 1,226 yards in the two years he shared the field with Marecic.
Marecic is a three-time all-Pac-10 honorable mention choice and now he's going to try and bring that same fierceness to the defense.
"Owen is the one guy who can do it," Stanford nose tackle Sione Fua said. "He's in the best physical shape of anyone on the team. He'll take a pounding, but he knows how to recover and he takes care of his body."
Marecic the fullback thinks he'd have the edge over Marecic the inside linebacker if they were to butt heads on the football field; based solely on experience.
After all, Marecic has been one of the top fullbacks in the Pac-10 the previous three years and there's no reason to think differently this time around.
Marecic was in on a handful of defensive plays last year and then was asked if he'd like to become a full-time starter on both sides of the ball.
Can you really save 15 percent on your car insurance? Will Stanford win another Director's Cup?
Give Marecic the choice; he'd probably like to spend his entire waking hours slamming into anything that moved on a football field.
"I like being on the field," Marecic understated. "You get into the rhythm of the game a little bit faster, like in high school."
He was Oregon's Defensive Player of the Year as a senior at Jesuit High in Portland. He was also a second team all-state pick as a running back.
This is no one-game experiment. Stanford coach Jim Harbaugh thinks Marecic will not only contribute but thrive in his new role. Marecic has yet to meet an opposing football player he wouldn't want to knock down.
"Owen has handled becoming a two-way player exceptionally well," Harbaugh said. "He's the face of this team. I don't know if anybody could have made a better football player than Owen."
Marecic can make a terrific block to spring a running back, or protect Luck and still be a little angry at himself. He's not successful unless he flattens an opponent.
"He gets excited," Fua said. "Even away from the play he's knocking down defensive backs. He's always looking for contact."
Marecic seems uncomfortable talking about himself, nervously rubbing his fingers against each other in a clinched fist. He looks you in the eye while answering, his voice nearly a whisper. His answers appear somewhat calculated.
There's no mistaking the intensity in his eyes though. It's as though he's sizing you up as a tackling dummy. This mild-mannered student turns into the Tasmanian devil once he reaches the gridiron.
"It's like, once he gets on the field, he flips a switch and goes all out," Fua said. "In the locker room he barely says anything."
He spent most of last spring learning to play linebacker after being used in goal line stands and short yardage situations last season.
"I just have to maintain focus and mental discipline," he said. "When it comes time to play I'll find a groove to do it."
Marecic deflected attention away from himself when the topic of leadership came up. Being the 'face of the team' as Harbaugh put it doesn't seem to make much of an impression on him.
"You can look all over the field, especially the seniors, for leaders like that," he said.
He does acknowledge a certain excitement among his teammates as the first game of the season approaches.
"It's buzzing a little now," he said. "Guys are getting excited. That first game, there is always something unexpected."
Fua said the defensive players want to create an identity for themselves this season. Marecic could go a long way in helping that happen. It starts in practice.
"We'll never take it easy on each other," Fua said. "We give it our all."
Just make sure Marecic gets somebody to knock down.