When Chris Culliver awoke three days after what was supposed to be a routine shoulder surgery, he didn't know he'd danced with death.

His surroundings slowly came into focus as the sedatives subsided, but he became increasingly disoriented. Why was a breathing tube in his mouth, why were countless other cords zigzagging across his body and why was a close friend crying at his bedside, moved by his awakening?

Eventually, the 20-year-old college cornerback would wonder just what in the world he was doing in intensive care at Palmetto Health Hospital in Columbia, S.C.

Didn't he just have shoulder surgery?

"I was like, 'Whoa,' " Culliver said. "I kind of checked myself and was looking around, 'What the heck's going on?' It was crazy."

It was also nearly tragic.

Culliver, 24, the 49ers' second-year cornerback, has malignant hyperthermia, a rare condition triggered by the drugs used for general anesthesia. Within 30 minutes after he was put under for surgery, his heart revved into overdrive and he went into cardiac arrest. He spent three days breathing through a ventilator as distressed friends and family prayed for his recovery.

"He was minutes away from death," said his mother, Marie Williams.

More than three years later, Culliver, a third-round pick in last year's draft from South Carolina, publicly discussed his experience for the first time recently. It was not publicized during college, and his mother, after making a passing reference to her son's brush with death, wasn't certain he'd share his story with a stranger.

After a lengthy pause, however, Culliver agreed to detail his ordeal during an interview following a 49ers practice. Like so many who survive near-death experiences, he said it erased any doubts about his mortality, providing an enduring gift.

"After you go through that," he said, "you cherish every day."

These days, Culliver has plenty to cherish as a key member of one of the NFL's best defenses.

In a season-opening 30-22 win at Green Bay, he batted away a deep pass for Packers wide receiver Jordy Nelson to seal the victory. Last Sunday, he was part of a stingy secondary that limited Lions quarterback Matthew Stafford to 67 first-half passing yards, allowing the 49ers to assume early control in a 27-19 victory.

Sunday's game marked the second time in two years that Culliver occasionally guarded All-Pro wideout Calvin Johnson. It was a challenge Culliver embraced in 2011 when, in his sixth NFL game, he forcefully instructed Johnson to stop pushing off after a deep pass fell incomplete.

It was typical of the confidence Culliver flashed as a rookie when he carved out a role as San Francisco's No. 3 cornerback, even though he played only seven games at the position in college. In 2011, quarterbacks had a middling rating (76.0) on the 53 passes in which they targeted the former safety, according to Pro Football Focus.

"He was a young corner and he believed in himself," safety Donte Whitner said. "And he could play. So he had a reason to be confident. Now people are starting to realize who he is and that he can play some football. He doesn't make young mistakes as far as blowing coverages or giving up big plays. He goes out there and handles himself like a veteran."

Childhood not easy

Culliver, who spent most of his childhood in Philadelphia, has navigated a painful path to achieve professional success.

His mother, 16 when he was born, raised Chris with help from her older sister, Markita Greenwood. During an interview, Culliver, after soberly answering football-related questions, flashed a megawatt smile at the mention of his mom's name. Williams, who graduated from Temple University, is a financial analyst in Philadelphia.

"It was a struggle growing up," said Culliver, who has a 20-year-old brother and a brother and sister, twins, who are 12. "But my mom has always been such a strong woman and has always been there for her children. That's why I love my mom the most."

As a child, Culliver began to develop a close relationship with his stepdad, James Jefferson, but Jefferson was murdered when Chris was 8. On Labor Day weekend 1996, a man opened fire at Jay's Big Shot Bar in Philadelphia, where Marie and Jefferson had gathered with other family members. Jefferson, 30, and Bernard Jackson, 33, Culliver's cousin, were shot in the back and killed. Marie survived after a bullet grazed her chest.

"That was really, really sad," said Culliver, who has a tattoo on his neck memorializing his stepdad, whom the family called "Tonk." "In my mind, he was my real dad."

Culliver went to live with his biological dad, Chris Culliver Sr., in Garner, N.C., after his freshman year in high school. Marie hoped Garner, a town of about 25,000 outside Raleigh, would provide a safe haven, a world away from the violence and negative influences surrounding her son in Philadelphia.

Culliver, who said he doesn't have a close relationship with Chris Sr., initially resisted the move. He was withdrawn and moody, prompting some classmates at Garner Magnet High to call him bipolar, he said. Not accustomed to receiving instruction from male figures, he didn't handle criticism well and often responded by sulking during practices. Defensive backs coach Chuck Proffitt recalled Culliver initially being distracted, a sign that issues beyond football weighed on him.

Proper guidance

James Payne, then a 29-year-old assistant who is the school's career rushing leader, knew Culliver's elite ability would be wasted without proper guidance. Payne reached out and the 16-year-old, normally wary and distrustful, quickly bonded with a man he calls a "big brother and mentor."

"He had talent, I saw that," Payne said. "But as far as life skills, he needed that guidance. That's really what our relationship was about. He believed in the things I was telling him about doing the right things, getting good grades in school, having self-respect, staying humble and working hard. ...

"I told him with the athletic ability he had, he could do something great for himself one day. He could take care of himself and his family with football, but it was just as important to be a great person. Don't just rely on football. He believed in that."

As a senior, Culliver, who played running back, wide receiver, safety and returned kicks, was rated the top recruit in North Carolina by Rivals.com and also made the honor roll. The sophomore who barely spoke had been transformed by the time he received a full scholarship as a senior.

"Once Chris made the decision to go to South Carolina," Garner head coach Nelson Smith said, "you'd always see this kid walking down the hallway with a huge smile on his face."

Though Culliver had discovered the correlation between hard work and success, his brush with death reinforced it.

In February 2009, Payne drove 220 miles from Garner to Columbia at 5 a.m. after learning about Culliver's condition. When he arrived, he was shaken by the sight of Culliver lying motionless and breathing through a machine.

"To see him in that bed, not knowing which way it was going to turn," Payne said. "But by the grace of God, he pulled through and everything worked out for the best. He'd already shown signs of really maturing. But that was a big thing that got him together. It's a big lesson. One day you can be here, and one day you can be gone."

In contrast with the day more than three years ago when he awoke disoriented, Culliver has clarity.

As he soaked in an ice tub outside the 49ers' locker room, he said he has added to what was already a substantial rookie workload. In his second season, he's lifting even more weights, poring over even more video and arriving at the facility even earlier than he did last year.

It's hard work, but for Culliver, it's also something else: a way to cherish every day.

49ers (2-0) at Vikings (1-1) 10 a.m., Channel: 2 Channel: 40 810, 107.7 Spotlight on: Nose guard Isaac Sopoaga. Remember this man? Sopoaga has played just 15 snaps this season as the 49ers have used sub-packages to get more defensive backs on the field against the pass-happy Packers and Lions. Now, the 49ers will face the Vikings, who want to establish the run with Adrian Peterson and Toby Gerhart. At 330 pounds, Sopoaga could double his season snap total Sunday as he faces center John Sullivan, who signed a five-year, $25.1 million extension in December. If All-Pro inside linebackers Patrick Willis and NaVorro Bowman are roaming free, it probably means Sopoaga is doing his job, which is to occupy Minnesota's linemen and make a mess of things up front. Injury notes: 49ers - RB Brandon Jacobs (knee) and WR Ted Ginn (ankle) are both questionable, and only Ginn has a chance to play. Ginn was limited in practice this week. Jacobs remained sidelined. Vikings - OLB Erin Henderson (concussion) is out and will be replaced in the starting lineup by Marvin Mitchell, who will be making the third start of his six-year career. He missed the season's first two games with a high ankle sprain. Henderson leads the team in tackles (20), tackles for loss (4) and sacks (2). Big Three -- Vikings WR Percy Harvin has caught 18 of the 21 passes on which he has been targeted, the fourth-highest catch percentage (85.7) in the NFL among players with at least 10 targets. The 49ers' Michael Crabtree ranks third in the category, with 13 receptions on 15 targets (86.7). -- 49ers RB Frank Gore is averaging 3.4 yards a carry after contact, which ranks sixth in the NFL, according to Pro Football Focus. Vikings RB Adrian Peterson ranks 25th in yards after contact (2.2). -- Vikings LT Matt Kalil, the No. 4 pick in the draft, is off to a strong start. Per PFF, Kalil hasn't allowed a sack or quarterback hit in two games. He has allowed only one pressure. Kalil often will go against Aldon Smith, who has two sacks, two QB hits and two pressures.