Not only was McGowan trying to come back from a major operation on his right elbow in 2005, he was learning how to deal with another obstacle. Not long after going under the knife so he could continue his pitching career, McGowan learned he also had Type 1 diabetes.
"I was rehabbing in the Florida State League that year, and it would get hot," a soft-spoken McGowan said Thursday at Knology Park, where he pitched that season for the Dunedin Blue Jays.
"When your blood sugar gets low, that's when you get a shaky feeling and you can pass out. I had that a couple times."
Two years later, McGowan can't remember the last time a similar spell occurred. He has adjusted to the new eating habits, and he currently has the disease under control. It's been just one more issue to overcome in his quest to make it to the Majors with the Blue Jays -- a goal that hit another snag this year.
"Now it's something I don't even have to think about anymore," McGowan said with a smile. "I have enough worries in my life."
McGowan was devastated by the news when he first learned he had the disease. The 24-year-old right-hander didn't know much about diabetes, except that it wasn't good. The symptoms were always there, but the connection was never made.
"My reaction was worse because I didn't know anything about it," McGowan said. "I just thought, 'This is bad.' Then I learned a lot about it and it's controllable. So, as long as I take care of myself, I can take care of it."
"That's a shock to you," Toronto manager John Gibbons said. "You don't expect to hear that about a healthy young guy like him. I'm sure that can wear on you mentally. He's battling a whole new lifestyle."
Type 1 diabetes is the worst form of the illness, which has no known cure. McGowan receives a daily shot of insulin to regulate his blood sugar levels, and he will do so for the rest of his life unless it gets worse. If the disease progressed, McGowan could be forced to wear an insulin pump 24 hours per day.
Jason Johnson, who pitched for the Indians and Reds in 2006, wears a pump when he is on a mound. So does Toronto Minor League pitcher Benjamin Harrison, who McGowan has turned to at times for advice on nutrition and other aspects of the disease.
"Mine, at this stage, is not as bad," McGowan said. "In time, I can develop into that. Hopefully, it doesn't. [Harrison] also wore the pump and he gave me information. He was just kind of telling me how to eat, and it's important that you eat a lot. It's important to keep a steady diet."
McGowan can't eat foods high in sugar content and said it was difficult adjusting to a completely new diet. He struggled with the nutritional program in 2006, when he arrived at Spring Training around 15 pounds below his usual playing weight.
He's in better shape this spring, but he's still a long shot to crack Toronto's rotation. Over the winter, the league granted the Blue Jays a fourth option year for McGowan because he missed most of 2004 after having reconstructive elbow surgery.
That means Toronto can send McGowan -- a first-round selection by the Jays in the 2000 First-Year Player Draft -- to Triple-A this year without exposing him to waivers. As Gibbons put it: "Good for the team, bad for the player."
"I knew there was the possibility. There's nothing I can do about it," said McGowan, referring to the fourth option. "I came to Spring Training thinking the same way. I'm trying to make the team. Either way, I was going to try to make the team."
As things currently stand, John Thomson, Tomo Ohka, Josh Towers and Shaun Marcum are all ahead of McGowan in the race for the fourth and fifth spots in Toronto's rotation. McGowan, who is 2-5 with a 6.69 ERA in 29 big-league games, appears ticketed for Triple-A Syracuse, where he'll work as a starter.
If there's something good that McGowan can take from the situation, it's that the Jays don't plan on moving him between starting and bullpen roles this season. Over the last two seasons, he's made 34 starts and 29 relief appearances between the Majors and Minors.
"That helps out a lot, because now I can get back into a routine and just concentrate on one thing," McGowan said. "That bouncing around was hard to do. Now I can be consistent."
It's one less thing for McGowan to worry about. That's welcome news for someone who's dealt with more serious issues in life.
McGowan isn't the only one with more peace of mind about his illness, though. The fact that he has his diabetes under control has also been something his coaches have been able to smile about, too.
"Those are the kinds of things that can wreck careers," Toronto pitching coach Brad Arnsberg said. "But Dustin has tremendous work ethic. Fortunately, I can't think of a time when it's affected him."
Jordan Bastian is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.