Clemson offensive coordinator Tony Elliott had just come back to the football facility from a haircut Thursday afternoon. He took time to peak into the quarterback room. Backup freshman quarterback D.J. Uiagalelei was watching film. Nothing new there.

"Then, coach walks in and drops the bomb," Elliott said of Dabo Swinney. "Trevor's out."

The news that star quarterback Trevor Lawrence had tested positive for COVID-19 didn't leak out of the building for about another seven hours. Once it did, the college football world once again turned upside down for the umpteenth time since the coronavirus shut down sports in March.

Inside that quarterback room, nothing changed.

"I was in the film room, chillin'," said Uiagalelei, the freshman who would skyrocket from five-star backup to phenomenon on Saturday. "Coach Swinney walked in. His face was kind of like I was in trouble. I was like, 'Dang, what did I do? Did I like a picture on Twitter I wasn't supposed to like? Did I tweet something wrong? … Then he told me Trevor wasn't playing."

No problem for the kid they call "Big Cinco". Big problem for those hoping there would be a hiccup a week before the Notre Dame game.

Swinney announced Saturday after a 34-28 win over Boston College that Lawrence will not be cleared for the showdown between the No. 1 Tigers and No. 4 Fighting Irish. But after watching a 19-year old start his first game and account for three touchdowns, it may not matter.

Clemson is set for next Saturday. Also for the next few years.

"Trevor Lawrence is going to be an incredible NFL player," Boston College coach Jeff Hafley said in praising his team's effort. "But Trevor's probably not going to be here next year."

Uiagalelei most assuredly will be -- with a rocket arm, monster legs and conviction just this side of cockiness. Clemson won again on Saturday, but this particular ACC result was dripping with significance. First, it was close. That almost never happens with Clemson. The Eagles threw a scare into the Tigers on Halloween. It was more than that.

It was close because Uiagalelei and tailback Travis Etienne didn't get together on a goal line hand off that resulted in a 97-yard return by BC for a touchdown. But it was also close because Uiagalelei and the Tigers then dug in and led a comeback from down 28-10 as Clemson's defense held Boston College to a shutout in the second half.

The Tigers hadn't been pushed this hard by an ACC opponent since early last season against North Carolina. They had not come back from a larger deficit in Death Valley since 1966. Their home winning streak (27) now is assured to span two presidential elections.

"I've been down before in high school," said Uiagalelei, who was still in high school 10 months ago. "Being down 18 points is not really a lot of points. I've been down 25 points before. I knew we were going to come back. "

Confidence doesn't even begin to describe the kid. Uiagalelei walked out of that film room Thursday afternoon to complete 30 of 41 for 342 yards and two touchdowns on Saturday. That big 6-foot-4, 250-pound frame accounted for another touchdown rushing.

Uiagalelei walked into a postgame Zoom call like he owned the room. He made taking over the nation's top team sound like going to the corner for a gallon of milk. He talked of getting a text from Reggie Bush. He had Nipsey Hussle and Mozzy pumping through his headphones before the game. Gold chains hung from his neck like rain. He particularly likes the "Big5inco" number reflecting his number (No. 5).

"I like chains," Uiagalelei said. "I like gold chains. I got a little bit of stipend money. I'll go get myself a gold chain."

That's American youth. It's also Clemson's quarterback for the foreseeable future. While in isolation, Lawrence told his replacement, "Any questions, call me." What could the presumed No. 1 pick in the NFL Draft have added?

"Today, I saw the culmination of what I've been pushing him for so long for," Elliott said of the new kid on the block.

Uiagalelei was made for this moment. He played for one of the best high school programs in the country, St. John Bosco outside of Los Angeles. The Braves play a national schedule. That means hopping on planes and playing out of state on national television.

When Clemson snagged Uiagalelei, it was another indicator of the program's lasting excellence. As a high school sophomore, he actually called the school to express his interest. Swinney told CBS Sports last year that Uiagalelei was only the second Californian he had ever signed.

"I felt like I was prepared," the quarterback said.

Let's hope Uiagalelei remains such an open book. His debut outshone a seminal moment for Etienne, who became the ACC's all-time rushing leader. Etienne came back for his senior season for moments like this. On this day, a new star was being born.

At his size, Uiagalelei is bigger than all but the defensive lines he will face. His long strides were on display on a 29-yard scoring run that cut the lead to 28-20 earlier in the third quarter. His second touchdown pass went to the wrong shoulder of leading receiver Amari Rodgers to make it 28-26. Rodgers reworked his body and caught it anyway.

"We've kind of been spoiled around here," Elliott said. "To see how Deshaun [Watson] and Trevor responded as freshman. They didn't respond like typical freshmen. We saw it from the day D.J. walked in here. He was going to be ready."