Clemson head coach Dabo Swinney smiles during his 2025 football camp in Clemson, S.C. Tuesday, June 3, 2025.

The Tigers are coming off their first ACC championship win since 2022 and first CFP appearance since 2020. They are a popular pick to repeat as conference champions and to achieve more.

Clemson has the eighth-best chance to win the national championship, according to ESPN's Football Power Index and DraftKings Sportsbook. It also has a Heisman trophy candidate with quarterback Cade Klubnik.

But to Swinney, Clemson is nearly the same team as last year. So, when ESPN's Rece Davis mentioned the Tigers could be ranked No. 1 in preseason polls, Swinney was astonished.

"We got the same team we had last year, so how are we preseason (No. 1)? What happened?" Swinney said during his sit-down interview with Davis and North Carolina coach Bill Belichick.

Well, a combination of factors from development and retention of homegrown players to Swinney using the transfer portal to the addition of a new defensive coordinator has Clemson viewed as a team to be a national contender.

Dabo Swinney's retention of top players has Clemson in prime position

Swinney touts that Clemson doesn't lose many players to the portal, and it delivered again this offseason. In the winter, they lost five players to the portal, the second fewest for a Power 4 program, and lost one in the spring. Each player who departed was not a starter.

According to ESPN’s Bill Connelly, Clemson returns the most production than any other team in Division I (80%). Klubnik was among players who returned for another season, along with top wide receiver Antonio Williams, offensive tackles Blake Miller and Tristan Leigh and linebacker Wade Woodaz.

Clemson also retained star contributors like defensive tackle Peter Woods, defensive end T.J. Parker, cornerback Avieon Terrell, linebacker Sammy Brown and wide receivers Bryant Wesco Jr. and T.J. Moore.

Clemson keeping key starters out of the portal is a testament to the culture Swinney created. It also retained third-year offensive coordinator Garrett Riley. Its experienced roster with a veteran quarterback and familiar coaches is among reasons why it is valued as a premier team.

Dabo Swinney lands largest transfer portal class in Clemson history

Clemson added three transfer players in the winter cycle: wide receiver Tristan Smith, defensive end Will Heldt and linebacker Jeremiah Alexander. These additions are more than what they have taken in the previous six years of the portal's existence (two).

"The crazy thing is we signed a portal guy three out of the last four years," Swinney said in February. "As I always said, we do what's best for Clemson, and I've always said we'll use the portal whenever we need it, and we'll be strategic with it."

Swinney was criticized for his lack of portal use last season as the Tigers were one of four FBS schools (Navy, Army, Air Force) to not add a transfer. Their inability to add a transfer, despite pursuing four offensive linemen in the offseason, came after they missed the CFP for a third straight season after making it from 2015-20.

Clemson made the playoffs last year despite not adding a transfer but immersed itself in the portal after roster spots came available. Smith, 6-foot-5, will add depth behind Williams, Wesco and Moore. Heldt is expected to play opposite of Parker on the defensive line to add another pass-rushing threat. Alexander will back up Woodaz and Brown and could be featured in Clemson's heavy personnel.

All three position groups suffered significant injuries last season. With these transfer additions, Clemson will have considerable depth if it suffers injuries in 2025.

Tom Allen may have be missing piece for Clemson football

Clemson's offense thrived last season, but its defense struggled. Clemson was 50th in the nation in scoring defense (23.4 points) and 69th in total defense (374.1 yards) last season under Wes Goodwin. Its biggest flaw was the run defense, allowing 160.6 yards per game (84th).

As a result, Swinney hired former Penn State defensive coordinator Tom Allen in January. The Nittany Lions were No. 8 in scoring defense (16.5 points), No. 7 in total defense (294.8 yards) and No. 9 against the run (101.9 yards) last year under Allen. He was a semifinalist for the 2024 Broyles Award, given to the nation's top assistant, and Swinney's fifth straight external hire.

Allen is Swinney's highest-paid assistant and carries intensity, personality and defensive prowess similar to former Clemson defensive coordinator Brent Venables. Allen said in the spring there is a difference between joining Penn State, a team that was top three in scoring and total defense when he arrived in 2024, to joining Clemson.

Still, Allen believes Clemson's defense is talented and experienced enough to be better in 2025. If its defense improves, it will be a key reason for it competing for the national championship.

Derrian Carter covers Clemson athletics for The Greenville News and the USA TODAY Network. Email him at [email protected] and follow him on X, formerly known as Twitter, @DerrianCarter00

This article originally appeared on Greenville News: How Clemson football became a popular 2025 CFP pick, even if Dabo Swinney might not agree