There is replacing experience, and then there is replacing Crezdon Butler and Chris Chancellor.
Butler and Chancellor played a combined 1,463 snaps at cornerback last season for Clemson's seventh-ranked pass defense.
The duo started 40 consecutive games together.
During the past three seasons, they manned their respective positions for 4,018 plays -- 74 percent of Clemson's No. 1 and No. 2 cornerback snaps.
Clemson never ranked lower than 13th in the nation in pass defense during their three years as starters.
With Butler and Chancellor in NFL camps, is the Tigers' coaching staff concerned about cornerback play as the team prepares for today's first scrimmage of camp?
"Yeah, Chancellor and Butler were pretty good players, great people ... they knew the system, they started the first play of a bunch of games," Clemson defensive coordinator Kevin Steele said. "But there's a lot of guys back there that played a bunch of snaps. (Xavier) Brewer played back there, (Coty) Sensabaugh, (Byron) Maxwell played a great deal. We've got a bunch of guys that have played a lot of snaps."
Maxwell (311), Sensabaugh (142) and Brewer (119) combined for 572 snaps last season. That is considerable experience, though the three combined didn't play as much as Butler (740 snaps) or Chancellor (723).
Despite the loss of experience, Clemson coach Dabo Swinney is encouraged much the way he was last summer with the safety position. Despite losing Michael Hamlin and Chris Clemons to the NFL, Swinney's confidence in DeAndre McDaniel, Rashard Hall and Marcus Gilchrist proved correct.
This fall at corner, Maxwell has the most experience after Gilchrist; the two are listed as co-starters on the depth chart. Swinney said Maxwell had a great opening week of camp and has "transformed" himself.
Swinney praised sophomore Spencer Adams for "turning the corner mentally" after Swinney felt he was not always "engaged" in 2009.
Swinney said Sensabaugh is in better shape.
The freshmen corners are promising, but Swinney said the staff needs more time to evaluate them.
Gilchrist appears ready to emerge from the shadows of Chancellor and Butler.
Some national analysts rated Gilchrist as a top-50 cornerback last year, but the senior was forced into a utility role, splitting time as a third corner and safety due to the presence of Chancellor and Butler.
"Gilchrist is just a machine," Swinney said. "He might be the best player, overall the most complete player on defense. The guy I'm most pleased with is Xavier Brewer. He has been tremendous. He has made himself very relevant."
Though there are only two corners in a traditional base defense, depth is important.
Steele said Clemson spent more time last fall in nickel defense (five defensive backs) than in conventional seven-man fronts. That means Clemson has to replace not only Butler and Chancellor, but also the nickel and dime (six DBs) production of Gilchrist and others last season.
In the age of spread offenses and pass-heavy tendencies, teams must play more defensive backs.
Still, the Tigers are confident their unit is deep and talented enough to meet the challenge.
"I think we see the game changing today," Gilchrist said. "The more receivers, the more (defensive backs) you need. I feel like we have a lot of depth, a lot of guys that can play."