Iowa may be without injured running backs Damon Bullock and Greg Garmon for at least another week, head coach Kirk Ferentz announced on Tuesday.

“I think Damon is doubtful,” Ferentz said. “And Greg Garmon, he’s probably got a little better chance than Damon does. We’ll see how the next couple days go before we make any judgments on that. So I think we have to plan as if both guys are not going to be there.”

The Hawkeyes’ depth chart for Saturday’s game against Central Michigan listed sophomore Mark Weisman, last week’s breakout star, as the No. 1 running back.

Weisman, formerly a fullback, took on ball-carrying duties when Bullock and Garmon suffered injuries in the second quarter on Sept. 15. Bullock took a defender’s knee to his head and lay motionless on the Kinnick Stadium turf for nearly a minute. Eventually he stood up and walked off the field.

Just minutes later, Garmon injured his right arm and left the game. Neither back returned to the game, but Weisman rushed for 113 yards in their place.

Ferentz said it was important to err on the side of caution with a head injury.

“The medical staff will tell us when they feel it’s prudent for him to return to action. We’ll just wait it out and see how things go,” he said. “We are not going to put him on the field until it’s more than safe.”

Quarterback James Vandenberg agreed.

“It’s something you can’t really mess around with, because that person is the only one that knows how bad those symptoms are and what it does to you,” the senior said. “So guys who have that, they need to take as much time as they need.”

While the health of Bullock and Garmon is unclear, Iowa reported some good injury news in the backfield: Running back Jordan Canzeri has been medically cleared to play. Canzeri suffered a torn ACL during spring practice in April, and Ferentz said Tuesday he hadn’t expected him back at all this season.

But the sophomore’s rehab went unusually fast, and Canzeri was dressed to play on Sept. 15.

“It’s just a matter of does he look good enough and is he confident to play,” Ferentz said. “That’s what a lot of injured players have to go through, but at least he’s moving forward, and it’s good to have him back in a uniform practicing.”

Still seeking first touchdown pass

Vandenberg threw 25 touchdown passes last season. Three games into 2012, he isn’t quite on that trajectory.

“Yeah, now I’m on pace for zero,” he joked on Tuesday. “It’s obviously going to happen at some point … But if we go 11-1 and I throw zero touchdown passes, nobody is going to care.”

A quarter of the season has come and gone, and the Iowa offense has yet to complete a touchdown pass. Tight end C.J. Fiedorowicz said nobody has started a pool on who’s going to snag the first.

“No, not yet,” he said. “Inside the 3-yard line, we’ve been giving the ball to Mark [Weisman]. But once Big Ten play comes around, I’m sure we’re going to have to mix things up. It’s not too big a deal as long as we’re winning. But yeah, that’s shocking.”