STORRS, Conn. — With only minutes left in the first half of Friday’s game, defender Karl Schilling jumped in front of a streaking South Carolina midfielder and lunged toward him in attempt to strip the ball. But as he did, the legs of the two became tangled and after some pushing and jostling for the ball, Schilling dropped to the ground.

Leg injuries are a common thing to see throughout the course of a soccer game. With all of the slide-tackling, legs flailing and even flopping going on, it’s not unlikely to see multiple players go down and eventually dust themselves off and continue on.

But this time was different — Schilling never got up.

As play continued on down field, Schilling laid face down in the ground, smacking the ground as he writhed in pain. The yell that he let out was so loud that you could hear the senior screaming in anguish from the top bleacher of Morrone Stadium.

“He twisted his knee,” head coach Ray Reid said. “Obviously he’s an important part of what we do and we just want to make sure that he’s healthy.”

After the ball was settled, the ref blew his whistle and the training staff trotted out onto the field. As they did, a shouting match broke out on the other side of the field with fellow captain Julius James and members of the Gamecocks who were being restrained by teammates.

Schilling was lifted to his feet, eyes squinting, teeth clenched, and with his arms resting on the shoulder of two members of the medical staff, was carried off. As Reid watched as one of his star defenders was being carried off the field, he ran his hand across the top of his thinning, neatly-trimmed hair and thought of what to do next.

The offense has put on a show in the first few games for the No. 14 Huskies (4-0), scoring a Big East-leading 10 goals and completely overwhelming opponents with their wealth of talent in the front.

But while the offense has received most of the attention and praise, the defense has arguably been the biggest reason the Huskies’ record still remains spotless. In four games this year, the defense has limited opponents to a total of 10 shots and two goals, both of which coming with nearly every member of the first team on the bench. With the likes of James, a two-time Big East Defender of the Year and 2006 first-team All-American, and Schilling, a third-team All-Big East selection last year, the defense has been absolutely stout, limiting opposing offense’s time of possession and helping goalie Josh Ford post three shutouts.

But with one of their leaders — someone who James says keeps the defense grounded — being escorted to the sidelines, Reid called for junior Oscar Castillo to be his replacement.

Upon hearing his name being beckoned, Castillo emerged from the metal overhangs that cover the bench and jogged to the out-of-bounds line. He crossed himself, gently kissed his fingertips and pointed in the air.

Listed at 5-foot-7, Castillo is almost the complete antithesis of Schilling and the rest of the starting defense. Unlike Kwame Watson-Siriboe, a 6-foot-3 monster who towers over opponents and James, an imposing figure with a strong jaw line and a penchant for getting carried away, Castillo is very unassuming.

“His confidence has wavered, he’s been unfit,” Reid said. “He’s a good player, but sometimes I don’t think he thinks he’s good. And that’s part of his problem.”

With a confused look across his face as if this were the first day of school, the junior saunters onto the field and takes a place next to the other Husky enforcers just outside the box — his rightful place.

According to Reid, Castillo, who transferred to UConn after playing two seasons at Division III Mt. San Antonio College, was supposed to come into Storrs and immediately take over the right back spot. But after summer workouts and all the preseason games were over, Castillo was relegated to the bench.

“I’ll be honest, we brought him in to be the right back,” Reid said. “At the point we got the kid, we thought it would be Karl and JJ [in the back]. We didn’t think Kwame could do it. But after watching Kwame all spring, we moved Karl out to the flank.” Within less than a minute from when he stepped on the field, Castillo received a pass on a clearing situation and quickly shot it up to midfielder Mike Pezza. But as South Carolina forward Schuyler Reardon arrived a second late, he gave Castillo a little shove after the play. But instead of making a scene, the junior acted as if nothing had ever happened and began to trot downfield.

Only minutes after his first action, Castillo dished the ball off to forward Chukwudi Chijindu and was again given a small push. But this time, Castillo ran farther up the field, and off a give-and-go pass from Chijindu, shot a laser at the net. The ball careened off the top cross bar to the dismay of the crowd, making a noise like a church bell that was louder than anything the reserved Castillo could have said.

“He hit the bar from 30 yards,” Reid said, chuckling. “We haven’t had a right back hit the bar in six years.”

Although the shot was the only one the junior would record, Castillo and the rest of the back four would go on to limit the Gamecocks to only three shots in the game — only one of which was on goal — as the Huskies prevailed 3-0.

“He was pretty good for a guy who had played about 8 minutes at UConn prior to [Friday] night,” Reid said. “That’s why we brought him in. We brought him here because we thought he would add a dimension of being a tough guy — a team guy. He’s not Karl — he’s a different look. But he’s a very good player.”

The defense would continue their tough play the next night. In a defensive battle that left both offenses struggling for the majority of the game, the Huskies refused to bend. Frustrating FIU and holding them to only four shots, the defense provided the time for O’Brian White to hook up with Akeem Priestley for the score with just nine seconds left in the 1-0 win.

While the diagnosis on Schilling — an MCL sprain that could leave him sidelined for 10 to 14 days, or more — wasn’t good, Reid said his defense should be just fine without him.

“Losing Karl Schilling is huge, but having Oscar Castillo is a good thing,” Reid said.