Ryan Shazier wasn’t the one holding his knee in agony after being injured in the first quarter, but the Ohio State linebacker felt Braxton Miller’s pain when the quarterback was knocked out of the game and carted off to the locker room.

“To me, it was almost heart-breaking when Braxton went down because we’re so close,” Shazier said. “When something happens to him, I can almost feel it in my stomach. Sometimes that even pushes me to play better.”

A hush came over a crowd of 104,984 when the Heisman Trophy candidate was being examined on the field. But coach Urban Meyer said afterward Miller probably could have returned if he was needed.

The Buckeyes, though, didn’t have to take that risk because they were giving San Diego State such a thorough beating without him.

Backup Kenny Guiton showed why he probably would rank in the top half of the quarterbacks in the Big Ten, and Shazier and the defense pressured and pulverized the Aztecs into numerous mistakes in a 42-7 victory Saturday.

Guiton passed for 152 yards and ran for 83 — both career-highs — and accounted for three touchdowns, and the Buckeyes allowed 99 yards while racing to a 35-0 halftime lead.

No Braxton, no problem.

“Kenny is one of the leaders on the team. He’s one of the captains, and everyone respects him and knows what he brings to the team when he’s in the game — a lot of confidence, a lot of swagger,” said senior receiver Philly Brown, who had two touchdown catches. “He’s a real vocal quarterback. When Kenny’s out there, nobody’s worried at all.”

Miller, who completed both of his pass attempts for 30 yards, was hurt on his first run with 12:02 left in the first quarter. One fourth-and-1 at the Aztecs’ 12-yard line, he gained five yards on a keeper. But his helmet flew off on the hit, and he stayed on his back. Trainers came out and began working on his left knee.

But Guiton, who has been in more rescue situations than an EMT squad, popped off the bench and ran an option on the next play, pitching to Dontre Wilson for an easy TD.

Called the ol’ right-hander by Meyer because of his knack for coming through like a star relief pitcher, Guiton handled the offense with poise throughout his stint. After a three-and-out on the next series, he hit Philly Brown on a 25-yard TD, dropping the ball in Brown’s hands in the end zone while getting drilled by a blitz.

The fifth-year senior finished off another polished TD drive at the end of the first quarter, keeping it alive with a 16-yard pass to Devin Smith on 3rd-\and-12 and handing off to Jordan Hall for the final three yards. That put an end to the angst in the audience.

“He’s (supposedly) too slow and doesn’t have a strong enough arm, but all he does is lead, manage and distribute,” Meyer said. “He has an incredible knowledge of the game and incredible leadership skills where players respond.”

Cornerback Bradley Roby (suspended) and safety C.J. Barnett (ankle injury) returned after a one-game absence, and the front seven turned into a disruptive force. The Buckeyes brought more blitzes and finished with three sacks and five tackles for losses.

“When you get your people back, you’ve got a chance because you’re aligned, you’re cohesive and I think our coaches get a little more comfortable calling pressures with everybody back,” Meyer said.

Shazier said: “It was great to have Bradley and C.J. back because it felt like a security blanket. If you mess up, those two guys know exactly what they’re doing, and they’re great players.

“I think our defense is better than people think it is.”