The look on Kelcy Quarles’ face was more fear than pain, though South Carolina’s junior defensive tackle felt plenty of both.

Hobbled on crutches, unable to put weight on his right knee, Quarles paused for a moment in the Neyland Stadium tunnel two weeks ago at Tennessee. Frozen in fear, the worst possible scenario entered his thoughts.

“To be honest, in my mind, I thought it was all over,” Quarles said. “But once I sat down with Clint (Haggard) and the training staff, Dr. (Jeffrey) Guy and all those guys, I knew I was fine. It was just a little knee sprain.”

Quarles thought he had no chance of playing Saturday at Missouri, just a week after his worst fears were avoided. Yet, like quarterback Connor Shaw, there he was — reduced to one healthy knee, but still making huge plays in South Carolina’s comeback win.

The junior finished with a team-high six tackles, including two sacks and three tackles for loss. On Monday, Quarles was named the SEC Defensive Lineman of the Week. His leadership was just as important.

Linebacker T.J. Hollomon said it was Quarles who got his team hyped before leaving the locker room. At halftime, Quarles ripped into the team for not playing up to its expectations. As the Gamecocks began their comeback, Quarles walked up and down the sidelines and told teammates to keep playing like they could win.

Hollomon, who also returned from injury last week, said it was hard to believe how Quarles was able to play as well as he did despite the sprained knee.

“Kelcy’s a freak,” Hollomon said. “I was in rehab with him last week, noticing how painful it was to get back, and for him to go out and have that game just shows how much he really loves his team and how much he really wants to give his all for the university. I really respect Kelcy for that. When he was in rehab, no matter how much it hurt or no matter how much he didn’t want to do it, he was just saying, ‘I have to do it. I have to do it.’ It was just a mindset.”

When the team flight returned from Missouri early Sunday, Quarles was too emotional to sleep. The adrenaline kept flowing through his veins. He tossed and turned in his bed until 4 a.m., eventually flipping on the TV. Images from the game played through his head. They kept playing in his dreams.

When Quarles woke up Sunday, reality sunk in. His body hurt — a lot.

“Sunday morning feels pretty bad,” Quarles admitted. “You wake up and get kind of that old-man groan. You just wake up and try to stretch and everything. You walk around, and you just want to sit back down and sit there for a little while, get your mind together, and then you can finally get up and move.

“It’s hard because you’re going against people bigger than you sometimes, quicker than you sometimes, stronger than you. I mean, you take a beating every play. We’re going against guys — grown men, basically. So, it’s hard.”

Quarles often makes it look easy.

None of USC’s defensive linemen have been as productive as Quarles this season, including star defensive end Jadeveon Clowney. Quarles ranks second in the SEC with seven sacks and 10 tackles for loss. Those numbers could land him on the All-SEC first team.

Gamecocks coach Steve Spurrier said Quarles’ production may be a byproduct of the extra attention opposing offenses have paid Clowney this season.

“Obviously, passing situations, Jadeveon has got two of them waiting on him over there just about every time,” Spurrier said. “So the other guys are pretty much one on one, and have a little bit more opportunities.”

At this pace, teams won’t be able to block Quarles with one lineman for long. Against Tennessee and Missouri, the junior had 10 tackles, five tackles for loss and three sacks.

Slowly, Quarles is starting to show he’s already a viable NFL prospect. He could forego his senior season, entering the draft with Clowney this April. On Tuesday, he deflected questions about his future at USC, and how much he’s thinking about professional football.

Sooner or later, he’ll have that chance.

“There have been several people coming to me, telling me about that,” Quarles said. “But I’m not worried about that at all. I’m worried about going out here, playing with my team, enjoying my teammates, enjoying this year we’re having, enjoying the time that we have together and just going out and getting better every day. When you hear stuff about that (NFL), you just have to stay humble and stay grounded.

“The Tennessee game was a real eye opener for me because, you never know, football can be over for you any day. So, you have to go out there, just play hard and not worry about the next day. Just worry about what you’re doing right now.”