The pain is a good part of why the former Komets tough guy retired in 2010. The injuries were loading up enough that the money wasn't worth the toll.
"I have no one to blame but myself," MacMillan said. "The things I did are my own. I did it to myself, and I knew full well. At the time, you don't think about the injuries or consequences. You don't understand that 15 years down the road you might not be what you were. The biggest thing is that every day you are a little stiffer. It's not like it's 10 years ago, and nothing seems to bother you."
MacMillan was always one of the most intelligent, thoughtful and articulate players in any locker room, and he's been thinking a lot lately about the game and what he did to play it, how it affects him now and what the long-term effects may be. It's only seven years later, and MacMillan admits he has a little bit of fear about how bad the future will be. He hears all the stories about mental problems concussions have caused former players, how some have taken their own lives and wonders if he'll be affected in some way as well.
"I know I have gotten my fair share," he said. "It's always in the back of my mind, what kind of damage did I do that I don't even know about? There's a very good possibility that you have done some permanent damage that may not show up until later in life.
"If I think about it too much, it's just going to eat me up. It terrifies me that these guys progressed down a slope where their minds were gone. They didn't even know it was happening at times."
But like 99 percent of all former players, MacMillan loved playing, and he'd do it all over again in a second. He'd just be a little smarter about it, more aware of circumstances.
"They always say you're going to regret it when you are older, but at that time it was so far away you couldn't think of it," he said. "I might have been a little injured, but I met so many good people at the time that it out-weighed a negative impact.
"You love the game so much and you want to do whatever you can to keep playing and never stop, and once you are done, you're like an old race horse turned out to pasture. You have a couple more limps and cracks, but it was the greatest part of my life, and I'd never want to do it any other way."
There's an old hockey adage that no one ever gets seriously hurt in a fight, but in the age of long-term concussion effects and bodies deteriorating post-career, that's really not true. MacMillan, 34, knows he earned almost every one of the 833 penalty minutes he received in 215 games over a six-year professional career. He's not making excuses or blaming anyone else for his current physical condition, but it makes him think pretty hard about the future of his sons Daegon, 9, and Grady, 4. He coaches Daegon's team, and his son has already seen all of his dad's Youtube.videos.
"What I went through, and what I'm going through and what might be ahead...," MacMillan said. "I look at Daegon, and if I can prevent him from going through some of the stuff I went through, I will."
Daegon is more of a skill player than his father, who compares his son's style to former teammates Colin Chaulk or Justin Hodgman. Daegon won't have to be a fighter unless he wants to. MacMillan said he won't be a hypocrite and tell his son he can't fight.
"My heart is kind of conflicted," MacMillan said. "There's the dad side of you that wants you to make sure that no harm comes to them, but on the other side, my dad told me not to do it and I didn't listen to him. He always told me that I was better than that and I didn't need to do it. He just didn't want to see me get hurt."
So besides his sons' futures, why is MacMillan bringing his concerns forward now? He's hoping some of today's players will read his story and make an effort to take better care of themselves so they may not have the same concerns after they retire. Wear better equipment, take the time necessary to heal and ask more questions of team doctors and listen to the answers better. Don't be afraid to protect themselves because life after hockey lasts a lot longer than a playing career.
He also talks regularly with friends who were fighters and understands their fear of the future unknowns. As he said, the only way to test for the severity of concussion problems is post-mortem. He still skates with friends in Fairbanks every week, and one of the major conversations is always past injuries and their current effects.
But sometimes, when someone will skate up behind and give him a whack on the leg, MacMillan is instantly back in predator mode, his neck hair standing up from the adrenaline rush, ready to spin and fire a punch. But he knows he really can't any more.
"I feel just fine, and I don't think I'm going to have any lapses," MacMillan said. "But I just don't know for sure, and that's the scariest part of it all."
For more on the Komets, follow Blake Sebring on Twitter at @blakesebring, at his blog tailingthekomets.com and on Facebook at Blake Sebring.