Saturday was Senior Day for the University of Minnesota women’s hockey team, so earlier last week, Amanda Kessel joined the other four members of her graduating class for an on-ice photo at Ridder Arena, their home rink. Kessel smiled, though the whole thing felt a bit weird. Kessel arrived with the class of 2014, not 2016. This became her class by happenstance.

“They were freshmen when I was a junior here,” Kessel said. “I got a new class. But it’s a good class.”

Kessel, 24, is just finishing her eligibility after missing one season for the 2014 Olympics and then the next year and a half recovering from postconcussion symptoms. The 2013 Patty Kazmaier Award winner as Division I’s best female hockey player, Kessel, a right wing, rejoined the third-ranked Golden Gophers this month. She has one goal and three assists in four games.
Only recently has Kessel, a former N.C.A.A. scoring champion and the younger sister of Pittsburgh Penguins right wing Phil Kessel, spoken in detail about her concussion and lengthy recovery.

It started with a freak accident in a United States national team scrimmage several months before the Sochi Olympics.

“Somebody tripped, took out my legs and I went headfirst into the boards,” said Kessel, who could not recall exactly where or when it took place.

Kessel, who sustained one concussion in high school, said she did not play for a month and a half. She sat out the Bring on the World Tour before the Olympics with what the team called a lower-body injury.

In Sochi, Kessel scored three goals and tied for the team lead with six points, as the United States won the silver medal. But after the Games, she said, things unraveled.

“Going into Sochi, I felt well,” she said. “Then a week and even months after, I noticed these weird things that I thought were normal, but they weren’t — sensitivity to light, headaches, fogginess, and I was nauseous all the time. I couldn’t figure out why, because I wasn’t hit again or anything.”

Josephine Pucci, an American teammate of Kessel’s, and Haley Irwin of Canada also missed significant periods with concussion-related problems before and after playing in the gold medal game in Sochi.

Instead of returning to the Gophers in September 2014 as planned, Kessel spent the next few months being treated at the Carrick Brain Center in Marietta, Ga. Dr. Ted Carrick, a chiropractic neurologist, helped Pucci and the former American Olympian Caitlin Cahow return to play, so Kessel was hopeful. But she still struggled.

“It took some of my symptoms away, but not what I would have liked,” she said. “I got my eyes back on track. They did everything they could to try and help me, and they’ve had a lot of successes with a bunch of my teammates. I think over all, it wasn’t the treatment that was going to push me where I needed to be.”

A physical therapist Kessel knew in her hometown, Madison, Wis., recommended she see Dr. Michael Collins, the highly regarded director of the University of Pittsburgh Medical Center’s sports medicine concussion program. Collins has treated hundreds of amateur and professional athletes, among them the Nascar driver Dale Earnhardt Jr. and Chicago Cubs catcher David Ross. Kessel said she started seeing Collins in June.

Collins declined to discuss Kessel’s treatment, but at a concussion conference at the medical center in October, he was among about three dozen clinicians and researchers who recommended physical activity for concussion rehabilitation. Kessel had stopped working out when her symptoms took hold, and she said Collins urged her to resume.

“That was really the main piece that started turning things around,” Kessel said. “Being a highly active athlete, and then doing nothing for a year and a half, that wasn’t helping my symptoms. I started working out, started doing things, and my symptoms continued to do better. Thirty minutes of cardio a day is pretty much what I was doing for a while.”

“At first it was tough, because I couldn’t understand why you were doing more when you don’t feel well. Then I really started to understand more and more what I was doing. A month into treatment, I re-enrolled in school.”

In September, Kessel took her first twirls around the ice since Sochi, alone.

“It was nice being back out there,” she said. “But right away, I missed the competitiveness of actually playing. It wasn’t so bad going out there the first four, five times by myself. But then I was ready to get in there and play with others.”

In July, Gophers Coach Brad Frost announced that Kessel would not play this season. That changed in January when she began practicing with her teammates. The university medical staff cleared her for games in early February.

“Back two or three years ago, I’m not sure she thought she would be playing hockey again,” Frost said. “Now over the last six months, to get back to where she is, 100 percent healthy, is just tremendous.”

Kessel led Minnesota to N.C.A.A. championships in 2012 and ’13, the second of those coming in a 41-0-0 season, the first undefeated campaign in Division I women’s hockey. She returned too late this season to help the Gophers (27-3-1), the defending N.C.A.A. champions, overtake their rival Wisconsin (30-1-1) for the Western Collegiate Hockey Association regular-season title.

The second-ranked Badgers swept Minnesota in a two-game series in early December in Madison, ending an 18-game winless streak against the Gophers. The teams meet again here Friday and Saturday in the final series of the regular season. Minnesota is 12-0-1 since losing to the Badgers and 3-0-1 with Kessel.

“She was gone for three years, and you wouldn’t know it the way she plays,” said the senior center Hannah Brandt, Kessel’s linemate then and now. “It’s awesome having her back. I obviously enjoy playing with her. It’s been a lot of fun so far.”

Now Kessel is thinking about another N.C.A.A. title bid, and perhaps the 2018 Olympics. She expects to graduate in August with a sports management degree — a little late, but healthy at last.

“It has definitely been a whirlwind,” she said.