Darnold, a 6-foot-4 sophomore rated by ESPN draft analysts Mel Kiper Jr. and Todd McShay as the No. 2 NFL draft-eligible quarterback, threw for 356 yards on 26-of-45 passing Friday night as the No. 5 Buckeyes beat the No. 8 Trojans 24-7 in the Goodyear Cotton Bowl Classic.
Ohio State sacked Darnold eight times. He threw a pick-six and lost two fumbles. The Trojans were held scoreless in the second half and scored only on a 15-yard drive in the second quarter after Ohio State's K.J. Hill muffed a punt.
"Right now, I think I'm really just focused on just hanging out with my teammates for the next couple of days and really just saying bye to the seniors, because they've put together such a great season," Darnold said. "But it's tough.
"I'll look at everything and make my decision after that."
Darnold shattered Carson Palmer's single-season school record for passing yardage, topping 4,000 yards in the Trojans' 14th game of a season that featured a Pac-12 championship.
He said he would consult his family, coaches and former players who have faced a similar decision. The deadline for underclassmen to declare for the NFL draft is Jan. 15.
"He's got all the time in the world," USC coach Clay Helton said. "And right now, it's just nice, like he said, just to go back and be with your buddies."
Helton, a third-year coach, said he would approach his discussion with Darnold as he did when he talked to cornerback Adoree' Jackson and wide receiver JuJu Smith-Schuster a year ago. Both former Trojans left school early. Helton said he would help connect Darnold with anyone he would like to receive advice from.
"The majority of what I've done is just to provide correct information -- where he could be drafted. What could happen if you come back? What's left out there? And just be a shoulder to lean on," Helton said.
A late hit out of bounds on Darnold by Ohio State linebacker Malik Harrison in the final two minutes sparked a fight on the USC sideline. The teams were assessed offsetting penalties, and USC safety Jamel Cook was ejected for leaving the bench area. Darnold escaped unscathed.
"Just an unfortunate situation," Helton said. "Tempers are going to flare in that situation, especially when your quarterback's over there. There's nobody that's maybe more loved on this football team than Sam."
Ohio State coach Urban Meyer offered praise for Darnold. But the Buckeyes' defensive line dominated the game, he said.
"We knew going into the game, obviously, he's going to be a top-five pick," Meyer said. "He's every bit of it. I was watching him warm up and going 'Whoa.' If you let that young man with those receivers just stand back and throw, you're not going to stop them."