(CNN) -- A Tulane University football player who fractured his spine in a head-on collision with a teammate during a weekend game is "alert and responsive" after surgery, the school's athletic director said Monday.
Devon Walker is expected to remain in intensive care for the next few days after a three-hour operation at St. Francis Hospital in Tulsa, Oklahoma, on Sunday, the Tulane athletics department said. Walker, a safety for the Green Wave, was injured Saturday when he collided head-on with a teammate while trying to tackle a Tulsa ball carrier.
Rick Dickson, Tulane's athletic director, told reporters Monday afternoon that he was "absolutely thrilled" with the reports of Walker's condition, but had few details to offer.
"Devon is alert and responsive," Dickson said. "How that manifests beyond that, I don't know how to respond." He deferred questions about whether Walker was able to move parts of his body to doctors, saying the senior was "in the hands of extremely competent and dedicated professionals."
Walker lay motionless on the Tulsa field as trainers and doctors rushed to him. Dr. Felix Savoie, an orthopedist for Tulane University and chief of sports medicine at the school, said after the game Walker suffered a "cervical spine fracture" as well as an edema, or swelling from a build-up of excess fluid, in his neck.
Tulane University's director of sports medicine Dr. Greg Stewart, who was with Walker on the field, said Sunday that, "for the most part, he was coherent" throughout the ordeal.
Medical personnel did do chest compressions on Walker similar to CPR, mostly because it was difficult to assess his cardiovascular health given all the football gear he was wearing, said Stewart. But once EMTs arrived, they determined the player's heart was stable.
Throughout the process and as Walker was loaded into an ambulance, Stewart said he acted like the player's "eyes and ears," telling him what was going on and to "relax, and being his calming voice."
Having been put in traction on Saturday, the more recent surgery to stabilize the spine involved putting a plate and screws on the front part of his spine so that the seven bones in his neck were on top of each other, the doctor explained.
The doctor said it is too early to tell if Walker is paralyzed in any way.
"The reality of this is that it takes time for these injuries to settle out, so we know what's going on," Stewart said. "We have another couple of days before we understand the extent of his injuries."
According to his bio on the Tulane athletics website, Walker is a 21-year-old senior majoring in cell and molecular biology. The New Orleans native, who weighs 173 pounds and stands 6 feet 1 inch tall, plays safety for the Green Wave, a team he's played with since walking onto the team and playing nine games as a freshman.
After the game, which Tulane went on to lose 45-10, Green Wave head coach Curtis Johnson described the mood in Tulane's locker room as "somber," calling Saturday "one of the most difficult days ever."
"I thought about just saying, 'Hey, look, let's not even do anything else, let's just get on the road and go," Johnson said of his feelings after Walker was hurt near the end of the first half.
Walker is planning to attend medical school after graduation, according to Johnson. The coach described the senior as a "self-made man" who was "probably the emotional leader" of his team, thanks to his "infectious" spirit.
"He loves life, and he loves football," Johnson said. "(Walker is) a very, very good kid, a very smart kid."
Professor Nancy Hopkins at Tulane said Walker had taken her biochemistry class in the spring of this year and was now registered in a biomedical writing course she teaches.
"He's a very pleasant young man," she said, noting that he always sits in the front row of her classes.
Walker has kept up with his study program while playing football and is on track to graduate in May, she said.
She described the outpouring of emotion on campus over Walker's injury as "amazing."
"This is such a tragedy, and we are all hoping and praying that he recovers," she said.
CNN's Joe Sutton contributed to this report.