CLEMSON -- The center of Robbie Caldwell's focus is his center.

NFL coaching great Paul Brown believed in building offenses from the center out. Former Clemson coach Danny Ford thought center was the second-most difficult offensive position to play after quarterback. And Caldwell, the new Clemson offensive line coach, prefers to place his best athlete at center.

The good news for Caldwell is junior center Dalton Freeman is one of the Tigers' best linemen along with right tackle Landon Walker. Freeman has the potential to be the first Clemson offensive linemen selected in the top three rounds of the NFL draft since Joe Bostic in 1979. Freeman is on the preseason watch list for the Rimington Award, given to the nation's best center, and if the Clemson offense is productive this

season, Freeman will likely have played a critical role.

"If you don't have to have another guy helping (the center) all the time, if he can do some things on his own, it frees you up," Caldwell said. "It allows you to do more offensively. If he can reach that nose tackle and handle that by himself, that's tremendous. But it's harder to do that nowadays, especially with the shotgun snap."

The center's challenge is more difficult today as opposing nose tackles typically weigh well over 300 pounds as the opposing defense's strongest players.

To better handle such a task, Caldwell challenged Freeman to become a stronger, more physical player this spring. Freeman has 102 knockdown blocks in 22 career starts, but Caldwell wants more. The 6-5, 285-pound Freeman will be aided by often practicing against Clemson's own 6-2, 310-pound nose tackle in Brandon Thompson.

"He's a real old-school type of coach," Freeman said of Caldwell. "Coach (Brad) Scott was very detailed, he was into some of the more modern techniques as far as (angle blocking) and getting the right hand placement. Coach Caldwell is more old-school: straight off the ball, hit them in the mouth and knock them out."

Freeman was thrust into the starting lineup as a redshirt freshman in 2009 and has improved each year. With another leap in productivity, he could give the Clemson offense an unsung asset, creating passing pockets for new starting quarterback Tajh Boyd and allowing guards to be freed to pull and trap in the running game.

Freeman could become the first Clemson interior offensive lineman to be drafted since center Dustin Fry was selected in the fifth round by the Rams in 2007.

And while becoming stronger, Freeman must also be in the best shape of his career to play 70 or more snaps per game in Chad Morris' up-tempo offense.

The offensive line as whole is thought to be a strength of the Tigers as they return four starters in Freeman, Walker, right guard Antoine McClain and left guard David Smith.

Phillip Price left spring as the leader to replace Chris Hairston and will be pushed by Brandon Thomas.

"We have a very veteran group of linemen, but a young core of skill guys," Freeman said. "I'm trying to step up vocally and bring them along. When I first took over, I was kind of looking around, looking for everyone else to pick me up."

Now it's time for the Clemson center to pick up his surrounding cast.