It's the only visible reminder of a serious ailment that could have killed the Canadian and top goalscorer in the NCAA.
It's the invisible reminders, the psychological impact of the health scare he suffered as a young boy, that Haber said helped shape the person and soccer player he is now.
The 20-year-old from Toronto has scored 13 goals to lead Cornell University to its best start in its history — 8-0-0. Cornell remains one of three NCAA teams without a loss or draw.
The junior striker continues to excel eight years after a rare brain infection gave him a new appreciation for life and sport.
"Maybe I needed to stop playing for a few years because when I came back to soccer I just had this hunger, enjoyment of the game, whether it was at practice or games, I loved being out there and moving around," Haber said after a communications class on Cornell's Ithaca, N.Y., campus. "I guess everyone has to find what they love to do and what I love is being with my friends on the field.
"I guess life is too short to not do what you love, and what I love to do is be on the field."
Haber was 12 years old when he developed a golfball-sized lump on his forehead that was eventually diagnosed as a rare bacterial infection — Pott's puffy tumour — believed to have been caused by a sinus infection that spread to his forehead.
The lump was moving dangerously close to his brain, which would have left him brain damaged or worse.
Five days after his 12th birthday, he underwent a five-hour surgery at SickKids which involved sawing off part of his skull. The cyst was removed and the skull cap reattached using titanium plates and more than 60 staples.
Haber spent two weeks in hospital. A nurse visited his house three times a day to inject drugs for three months after that. He eventually returned to playing soccer and hockey, but didn't feel at ease on the soccer pitch, so didn't play competitively again until Grade 11.
Cornell coach Jaro Zawislan spotted Haber at a showcase tournament that year and invited him to a camp that same summer. The coach clearly liked what he saw, offering Haber a spot on his squad.
"Right away we knew he was a quality player, and that he would be able to contribute sooner rather than later, at the Division 1 soccer level," Zawislan said. "We knew that he was a threat on the attacking side, quality finisher. We talk about athleticism, speed, the explosive side of it, the technical side of it, tactical awareness, mental strength.
"Getting to know him through the recruiting process we learned about his character qualities. He showed how driven he was to keep improving day to day to become a better and better soccer player and to fulfil his potential."
The five-foot-10 Haber is coming off four goals and two assists in a pair of games that earned him Ivy League player of the week for the third time in four weeks. He added another two goals in a 4-1 victory over Hartwick on Tuesday night.
Haber, who also leads the NCAA in points per game with 3.71, shrugs off the individual accolades, saying his success is as much a product of his teammates.
"It's just a credit to how many opportunities we're creating as a team, and whether it was me scoring or someone else scoring, it doesn't really matter," Haber said. "I really just like making plays, whether I'm the one to put it in the net or not doesn't make a difference to me. I love being part of the attack and helping break down defences.
"Setting up my teammates usually feels better than scoring myself, it just happens that this season it's been more of me. But being able to do it for the team is all that matters."
Zawislan said it's obvious in the way Haber prepares for games and training that his star striker takes nothing for granted.
"He just lives that soccer experience to the fullest, he as well as anybody else in our program," the coach said. "Everybody knows here whatever we get out of the season, whatever we get out of those games we'll have to earn it.
"And that's something that's been ongoing theme here in our locker-room, that there is no sense of entitlement, there's no sense of anything coming our way unless we earn it on the field."
Haber helped secure his spot at the Ivy League school with an application essay about his experience as a young boy, entitled "My Life-Changing Experience."
He wrote about how it was the first serious blow he'd been dealt in his life. There had never been any deaths in the family, nor even any serious illnesses.
"It just gave me a new perspective on life, how close I was to getting serious damage in my brain," Haber said. "And being in the hospital around people who were all sick with various conditions, anywhere from being there for day treatment to being there for months or years, and some never being able to heal, people who had gone through some serious stuff and it really gave me a new appreciation on how lucky I was."
Haber applied to volunteer at SickKids several times following his illness, but was told he was too young. He was finally given permission in the summer after his freshman year at Cornell, working in the cancer unit.
"For a lot of the kids, they can get lonely, and some of them are there permanently, they've been there for two or three years," Haber said. "Just having someone to be there and play, make you smile, or just talk to if you needed to get something off your chest. . . it was definitely something I wanted to do, to give back to the hospital. They saved my life, I owed everything to them."
Haber received other scholarship offers to play in the NCAA but an Ivy League education was something the Canadian striker said he couldn't pass up.
Zawislan, a former Toronto resident who has dual Canadian and U.S. citizenship, regularly travels to Toronto to scout Canadian players.
"We try to keep an eye on Canadian talent because Cornell being the closest Ivy League school to Toronto area, it just makes sense geographically," the coach said. "We definitely cover that area thoroughly, exactly for that reason, for opportunities to identify players like Daniel."
Cornell has eight games to go in the regular-season, and was scheduled to host the University of Pennsylvania on Saturday.