"I had a two-year contract to stay in England. But I'm 36, I don't want to get hurt.
"I don't have any nagging injuries but if I play one more year I could break my leg, tear an Achilles, maybe injure my back, who knows? And for what?
"To play another 50 games?"
The big man's past struggles, hard-earned experiences, his ongoing battle with alcohol, have been well documented. And are only part of the reason folks in this town have taken him in as one of their own.
Following retirement, mid-September, of course, McGrattan was hired by the Flames in the role of player development/player assistance, joining another former troubled tough guy, Brantt Myhres, brought on board by the L.A. Kings in a similar capacity two years earlier.
Six months in, the gig is going well.
"I have," McGrattan reminds you needlessly, "pretty much seen it all.
"They could've hired any professional, a counsellor, what have you. But a player might not feel comfortable talking about his problems with someone like that. We can relate. They know where I've been, what I've been through.
"They know I'll listen and I'll understand.
"On the flip side, they're not going to be able to put anything past me, either. Trust me. I've been there."
Over two tours of duty here, McGrattan morphed into an unlikely crowd favourite. His post-dust-up salute to fans on the way to the penalty box is the stuff of current lore.
During his career, he may have clocked in as an Ottawa Senator, a Phoenix Coyote and a Nashville Predator, too, but the Scotiabank Saddledome is his address of choice.
"This is where I feel at home," he says.
"This is why we stayed. I love Calgary. I loved playing for the Flames."
And they, in turn, loved the man known far and wide, hither and yon, as Big Ern right back.
"We were on the way back from a road trip my rookie year playing in Binghamton,'' McGrattan says, explaining the genesis of his signature nickname. "We're having a few pops on the bus and the movie Kingpin is playing. And one of the guys on the team, Josh Langfeld, jumps up and yells: 'Big Ern McGrattan!', instead of McCracken, Bill Murray's character, right?
"Well, everybody starts laughing.
"And it stuck."
The transitioning away from the on-ice has proven to be smooth.
"I'm lucky," he says. "I have an opportunity to still be at a rink every day. I get to be around both the Flames and Stockton. We have our alumni skates and I skate with some buddies so I get to be on the ice as much as I want, too.
"You know, retiring is a pretty big step. Usually when people retire they're in their 60s, right? I'm in my mid-30s. Through the last couple years I've tried to make as many relationships as I could, had a bunch of ideas of what I might like to do. I was planning on just shutting down for six months or so, while keeping in contact with the Flames.
"Job-wise, right from the beginning Brad (GM Treliving) and management made me feel so comfortable. It's made it easier, kinda being part of their team."
McGrattan says the mentoring time in Stockton, with the kids, many still in their professional infancy, has been particularly rewarding.
"The relationships have started to build between myself and our future Calgary Flames. So a year or two years down the road, when they're hopefully playing here, they'll feel comfortable coming to me if they're having a problem.
"It hasn't happened overnight. You have to earn the trust, build those relationships."
McGrattan's victories aren't found in standings on the internet or in punch-counts anymore. They happen when feisty Ryan Lomberg, seven inches shorter, envelopes the 6-foot-4-inch McGrattan in a bear-hug upon receiving news of his first shot in the NHL.
Or when Morgan Klimchuk, after his first call-up, pulls McGrattan aside and says: 'Man, thanks for that talk we had a month ago.'"
All the feedback has been positive.
In Stockton on the weekend, he met up with a pal - San Diego Gulls' head coach Dallas Eakins - and the two men sat in the coaches office, shooting the breeze.
"He told me: 'I told you two years ago there was going to be a need for your position in this league. It's slowly coming and one day every team will have someone like you.'
"Look, 95 percent of the guys might not need me, ever. But if there are one or two guys each year who have some stuff going on outside of the rink and I can help, in any way, I want to be there for them.
"Maybe they don't feel they have anyone to talk to, so they keep it inside.
"So it could just come down to meeting with a guy every couple of weeks, making sure he's keeping it between the lines, making sure he's comfortable."
Vitally, he adds, the Flames' organization has allowed him the space to do a job that is balanced delicately between the players and management.
"I may be in the middle but I'm not in an awkward position. The fact that coaches and management don't bug me about who I'm talking to or what we're talking about is so important.
"For the position to work, that's the way it has to be. The organization and the players trust me.
"That's why they wanted an ex-player in this job, someone the current guys know played hard for his team, was loved for that and had a good reputation among this teammates.
"The players know here in Calgary know that whatever we talk about doesn't leave the conversation. It could be about anything. Anything. And I think that's comforting for the guys in the room here."
The seeds for his new post began to be sewn in early summer.
"Brad and I have known each other for a decade now. When (Emile Poirier) had his struggles last year, I met with Brad and we talked. I said: 'Just leave him with me. I'll get him on the program I was on when I got out of treatment. It's a good program.'"
The first follow-up was a request for a lifestyle presentation prior to the development camp for prospects.
The second follow up was a surprise - a job offer.
"More or less a dream come true," the big man acknowledges. "I get to be in the NHL again. I get the chance to maybe be a factor is someone's career, someone's life, in a positive way.
"I get to be part of a team again. I get to be a part of an organization in a role that they, and I, feel is needed."
Yes, he'll happily concede that being Brian McGrattan is pretty sweet right at the moment.
"When I was struggling with my stuff outside the game,'' he says, "the alcohol and drug abuse, there's no light. You don't see anything.
"Life is … hard.
"But I put the work in away from the rink. It's been a day-to-day process for almost a decade now. The people in treatment centres don't lie to you - If you continue to do good things daily, good things will happen.
"And they have.
"But I never lose touch, never lose sight, of where I was, where alcohol and drugs can take you. It's one of the things that keeps me on my toes, in my program, doing my day-to-day stuff.
"I had a decent career, played 15 years of pro hockey. I was able to leave the game on a good note. I have an awesome job. I have a wife and a son. My family life is great.
"If you were to tell me 10 years ago what I have in my life today, well … I'd have told you you were crazy."