T.J. Barnes is a very large person.

At 6-foot-7, 325 pounds, he’s Georgia Tech’s biggest player, and an even bigger asset this week.

As a defensive tackle on the scout team, he is giving Georgia Tech’s offensive linemen a picture of the heavy challenge that awaits them Saturday at Boston College.

“We love him,” said co-offensive line coach Mike Sewak said of Barnes. “We wish we could clone him and make about four of him.”

Saturday’s game could be decided by the players that Barnes is impersonating — B.C. defensive tackles Ron Brace and B.J. Raji — and those assigned to block them. In the opening ACC game for both teams, Boston College offers brawn aplenty on the defensive line. The two tackles’ average weight is 323.5 pounds, about 28 pounds more than the average weight of Tech’s three interior offensive linemen.

What Tech’s offensive linemen will bring to the fight is less clear.

“Our kids, they’re still learning,” Sewak said. “But I think this will be a great challenge. That’s what you play this game for.”

The challenge has different facets. Coach Paul Johnson said he thinks Boston College’s defensive line is among the best in the country. Brace is on the Outland Trophy watch list. Raji was a second-team all-ACC pick in 2006 before sitting out 2007 for academic reasons. They’ve started 51 games and weigh a combined 647 pounds. Ends Jim Ramella and Alex Albright have a combined 13.5 career sacks and helped shut out Kent State in the Eagles’ season opener last Saturday.

Further, Georgia Tech’s front five — tackles David Brown and Andrew Gardner, guards Joseph Gilbert and Cord Howard and center Dan Voss — don’t have much experience. Gardner will make his 41st start Saturday. But prior to last week’s season opener, none had started a game in their current positions. Gilbert is a redshirt freshman who will play his first road and conference game Saturday.

Further, they’re still feeling their way through Johnson’s offensive scheme. Sewak said “we did a poor job” making even simple adjustments in the season-opening win over Jacksonville State last week.

A failure by the offensive line to create holes for B-back Jonathan Dwyer and give quarterback Josh Nesbitt operating room will spell doom for Georgia Tech against the Eagles.

“The onus is on those guys up front,” Johnson said Tuesday. “They’d better get their tail in gear and they know if they get physically slapped around, we’re going to have a hard time.”

Georgia Tech’s success will depend on a few things. Improving from the first game and using proper technique are two. That’s where competing against Barnes helps.

“Get low, just try to drive your legs and keep working at it,” Voss said of his methods. “It’s pretty hard to push him back.”

Strategy is another.

“We’ll have to run different blocking schemes to maybe make them think a little bit,” Sewak said. “But for the most part, it’s going to come down to man to man and hopefully we’ll have some of our guys step up. And if not, it’s going to be a long day.”

While acknowledging the challenge, Voss, who will give up 30 pounds to Brace and Raji, won’t shy from the fight.

“I can see why there may be a question mark, but I don’t listen to it,” Voss said. “We’re going to go out there and turn that question mark into an exclamation point.”