While Heitmann hasn't been visible at training camp, the ninth-year pro is doing a lot behind the scenes these days to help prepare an offensive line featuring a pair of first-round rookies and David Baas filling in at his spot snapping the ball to quarterback Alex Smith.
Heitmann, using crutches and wearing a walking boot over his lower left leg, isn't ready to guess exactly when he will return. Speaking formally Wednesday for the first time since the injury, the 30-year-old Heitmann insisted he's doing all he can to be back within the six- to eight-week window that he's expected to need to heal.
"You always kind of want to give yourself dates to shoot for. This is a different injury than what I've experienced before," Heitmann said after watching one of the Niners' most spirited practices yet this camp. "Just know that I'm doing everything I can to ensure that I'm back as soon as possible."
With a broken bone, it just takes time to heal -- so there's not a lot he can do from a football standpoint yet. He's taking calcium pills to try to speed up the process. He's not sure how long he will need the boot and crutches, key stabilizers and protection while the bone is repairing itself.
Heitmann has started every game at center each of the past three seasons. He played 14 games there in 2006 before breaking his right leg, needing surgery and missing the final two games.
Replacing someone as essential as the guy who snaps the ball to the quarterback is a tough task. Baas hasn't played center regularly since his senior season at Michigan but played one game there at the end of the '06 campaign in Heitmann's place.
Heitmann is trying to help in any way to make the transition that much smoother. He even takes notes for his teammates on what they're doing.
"There's a lot I can do. I'm definitely very active in all the film sessions," Heitmann said. "I'm trying to do everything I can right now to help the young guys, seeing blitzes, seeing the field, helping with the calls, anything I can do to mentor and help this team right now is exactly what I want to do."
He has been attending meetings and offering his input, experience and expertise when it comes to coverages and reading defenses.
Offensive coordinator Jimmy Raye has appreciated Heitmann's hands-on approach even while sidelined.
"Eric is like the backup quarterback. He is the quarterback of the line, so he is very good on fronts and potential pressures and line calls," Raye said. "We still involve Eric in the meeting at night when we go through the tape as a unit together. Alex makes the call and he makes the line call, so it helps to have his experience with the young guys and in particular David because he may see it one way and Eric, through anticipation and experience, sees through what he sees to get to the right thing."
The 49ers still haven't had their regular offense together yet, something Raye sure would like to see soon. Running back Frank Gore is expected to play for the first time this preseason Saturday night against the Oakland Raiders and second-year receiver Michael Crabtree could get his first action after missing time with a strained neck.
Pro Bowl tight end Vernon Davis is still nursing a strained right knee. He said he won't play at Oakland but plans to take part in the entire preseason finale against the San Diego Chargers on Sept. 2 if the coaches allow him to go four quarters.
Davis didn't get to participate in a practice that featured plenty of back-and-forth fun between the offense and defense, though the regular trash-talker likely hollered a few words from the sideline to get in on the action.
"I want to be out there bad," Davis said. "I'm ready."
So is Raye -- to see his team intact at last.
"The continuity we have to have, we still haven't had that," Raye said. "We haven't gotten that all together yet."