A little more than a week into training camp, the Miami Dolphins' offensive line is riddled with question marks.

Pro Bowl left tackle Jake Long has yet to practice because he's on the physically unable to perform list. Vernon Carey has been moved to right guard after starting all of last season at right tackle. Veteran right tackle Ray Willis was signed Saturday, a few days after former Dallas starter Marc Colombo came aboard.

In the middle of the line and the middle of all the uncertainty is Mike Pouncey.

The Dolphins' first-round pick has been lining up at center with the first-team offense since July 31 — even though 2010 starter Joe Berger is still on the roster. Pouncey missed the first two days because he was unsigned.

Pouncey knows he's a key piece in the rebuilding and reshaping of the offensive line.

"It's high expectations, man," he said after Saturday's practice. "That's why they're paying me, to come in and learn the playbook fast, come and help this team win ballgames. I'm up for the task. I'm putting in all the extra work so I can be out there and not let anybody down."

Pouncey, the 15th overall pick in the draft, has been playing catch-up since signing his contract and taking part in his first practice last Sunday.

"I held out for the first two days and then I came in and they threw the playbook at me and I had to go out there with the ones," he said. "All those guys being here knew the playbook, so it was tough the first day. But as I've been going along in practice, it's been getting better and better and easier and easier."

Coach Tony Sparano has been impressed by what he's seen.

Asked to point out the thing he has liked most about Pouncey in the early stages of camp, Sparano replied: "The list is long. If I had to pick one that I like the most about him ... I can't pick one, I'd have to pick two: his disposition and his athleticism."

Those are some of the same traits that helped Pouncey's twin brother, Maurkice, become a Pro Bowl center as a rookie last season with the Pittsburgh Steelers.

Pouncey spent the offseason training with his brother, but now that camp has started, there's not much advice Maurkice can offer.

"None at all," Mike said. "I mean, he's up there helping his team. He just said go out there and work hard. That's the only advice he can give me."

Pouncey took over at center for his brother at the University of Florida last year after starting at guard, and much was made of a few errant shotgun snaps he had. When Pouncey was drafted, the Dolphins listed him as a guard/center. But Sparano said early in camp he would be at center.

Now it's up to Pouncey to keep learning and provide at least one answer for the Dolphins. By all appearances, he's off to a good start.

"I just think my talent put me where I needed to be," Pouncey said.

"Physically I can go out there right now and play with any team. Just mentally, I've got to keep getting better and better each day."