CHARLOTTE, N.C. – What if?

They’re the two saddest words in the English language. Especially if you happen to be associated with or root for Clemson football.

The Tigers won the ACC championship on Saturday, their 7th in the past 8 years, by beating North Carolina 39-10. But even as Dabo Swinney and his players reveled in their victory on the field at Bank of America Stadium, there was a cloud that hung over their celebration.

And it wasn’t the billow of white confetti shooting over the festivities out of air cannons.

It was the figurative specter of what might have been.

What if …

What if Swinney had replaced struggling quarterback DJ Uiagalelei with backup Cade Klubnik in the 3rd quarter of last week’s regular-season finale against South Carolina instead of waiting until the 3rd possession against the Tar Heels?

Considering that No. 3 TCU and No. 4 Southern Cal both lost their respective conference championship games this weekend, there’s a realistic possibility that Clemson would be heading to the College Football Playoff later this month rather than a lesser date in the Orange Bowl.

We’ll never know for sure, of course.

But after watching Klubnik terrorize an admittedly bad UNC defense and show why he was the nation’s No. 1 quarterback prospect in last year’s recruiting class, the answer seems clear.

The highly-touted freshman completed 20-of-24 passes for 279 yards and a touchdown. Seven of his completions went for 15 yards or more. He also ran for a score and caught a pass for 19 yards on the way to becoming the 1st true freshman to earn Championship Game MVP honors.

But the raw numbers, as impressive as they are, only tell a small part of the story.

Before he entered the game to a standing ovation with 5:58 left in the 1st quarter, Clemson had run 6 plays. Five were passes by Uiagalelei. With only 2 completions for 10 yards.

UNC led 7-0 at the time.

Klubnik immediately lit a spark. He completed his first 5 passes for 50 yards and ran the ball 3 times for 18 more on a 9-play, 71-yard drive that ended with a 1-yard touchdown pass to tight end Davis Allen.

“We went into this game (planning for) him coming in on the 3rd series no matter what,” Swinney said. “DJ did not play well the first 2 series’ and we didn’t know what (Klubnik) was going to do. But he came in and really played well and we rolled the rest of the way.”

Swinney and offensive coordinator Brandon Streeter told their young quarterback of their plan to play him against UNC last Sunday. Klubnik said he prepared for the opportunity as he always does.

The difference this time from the previous chances he was given to take over the offense and make his own — earlier in the season against Syracuse and Notre Dame — came when when he trotted onto the field for that first series.

“I think I had a little different mindset today,” he said. “I’m not exactly sure what it was. But I was pretty pumped. I came ready to play free.”

And it wasn’t just his play. Klubnik’s coming-of-age moment also included his emergence as a leader as he came back to the sideline after the initial touchdown drive.

“I just talked to the offensive linemen and receivers, like ‘this is just the start. Let’s keep on rolling,'” he said. “We had a great 1st drive. I was really just trying to encourage them to don’t be satisfied with 1 good drive. Let’s go get 5 or 6 more.”

So they did.

The 2nd touchdown came just 66 seconds and 2 plays after the first. Cashing in on a Tar Heels fumble, Klubnik got his team in the end zone again for the go-ahead score. And the Tigers were off and running.

It was a similar spark to the one the youngster provided after relieving an ineffective Uiagalelei in a win against Syracuse on Oct. 22. It’s the kind the Tigers desperately could have used as they battled to hold off South Carolina and keep their Playoff hopes alive.

But Klubnik never left the sideline.

Whether it was out of stubbornness, loyalty to Uiagalelei, a lack of confidence in his young backup or some other reason, Swinney stuck with his starter.

It cost him dearly.

Uiagalelei threw for only 99 yards in the game. Eighty-six of them came in before halftime. He was just 3-of-16 for 13 yards and an interception during a 2nd half in which the Gamecocks rallied from a 23-14 deficit to a 31-30 win.

Clemson entered that game ranked 8th. With Ohio State getting knocked out of the top 4 by Michigan and the previously mentioned losses by TCU and Southern Cal, a strong case could be made that a 1-loss ACC champion would have jumped a 2-loss SEC non-division winner.

Especially after passing the eye test with its rout of UNC.

But that didn’t happen because Swinney waited too long to make the change that gave his team its best chance at winning.

“Hindsight’s always 20-20,” he said, adding that he doesn’t think Uiagalelei was the reason Clemson lost the game. “There’s a lot of things I wish we could have done over. But you don’t get a chance to do that. It’s all about what’s next for us.”

What’s next for the Tigers is a trip to the Orange Bowl. And a long offseason of asking themselves the saddest of questions as they place their latest ACC championship trophy onto the mantle.

What if?