But a year earlier, he had been at Lansing in the low Class A Midwest League, where the fifth-round Draft choice in 2007 was 7-6 with a 2.83 ERA in 22 starts in his first full professional season.
While with the Fisher Cats, the Blue Jays' Double-A affiliate in the Eastern League, he talked about pitching at a higher level and about working on his changeup, which he feels he did not use enough at Lansing.
Promotions have come quickly for young pitchers in the Blue Jays organization this year, and Rzepczynski was about to hop on that elevator.
After going 7-5 with a 2.93 ERA in 14 starts with the Fisher Cats, he was promoted to Triple-A Las Vegas, where he was 2-0 with 0.79 ERA in two starts (June 24 and 29).
His next start was for the Blue Jays, on July 7 at Tropicana Field, a six-inning no-decision against the Rays in which he gave up one run and struck out seven.
He has been with Toronto since, and after going 2-4 with a 3.67 ERA, he is finished for the season because he has reached his allotted number of innings worked.
Though the left-hander is in the Majors, Minor League totals that are in effect for young pitchers have been invoked as a precaution. Rzepczynski has pitched a total of 149 1/3 innings -- 88 in the Minors and 61 1/3 in the Majors.
"They usually say an increase of 20 to 30 percent a year for young kids," Rzepczynski said. "I guess they don't want to overwork us -- not that we're going to tire out this year but for next year. That's the thing, is building up innings."
At nearly 150 innings for the season, he said, "I can't ask for much more where I've been this year."
Another left-handed rookie starter, Brett Cecil, soon will be shut down for the rest of the season. But with 132 innings combined between the Minors and Majors this year, he likely will have two more starts.
Rzepczynski's final start of the season was a loss to the Rangers in Arlington in the first game of a doubleheader on Sept. 1, when he allowed three runs on eight hits, walked two and struck out nine in six innings.
After talking about adjusting to Double-A hitters, slightly more than three months later, he was talking about big league hitters.
"The hitters, of course, are better," he said. "You have to make better pitches. They sit on pitches more. If they get it, they hit it a long way. You can get away with a few more pitches there than here.
"It's just basically, you ask any pitcher, is to just stick with your game. So that's what I've done for the most part, just fine-tuning stuff and going from there."
Rzepczynski is a sinkerball pitcher, and his pitches move. Minor League pitching instructor Mel Queen says that Rzepczynski is a throwback, a lefty who would have trouble throwing a ball straight if he tried.
"It just happens to be where my arm angle is," Rzepczynski said. "I have a high three-quarters arm angle. It's been my natural arm slot all my life, and I haven't changed it at all since I was five years old."
And because of that consistent arm slot, he knows that most of the time, his two-seamer will run down and away from right-handed hitters. He tries to keep the ball down. If the pitch is up, it flattens, and he is in trouble.
Rzepczynski also throws a four-seam fastball, a pitch that goes straighter and that is used to go in on right-handed hitters. His other pitches are changeup, curveball and slider. He goes mostly with his sinker and slider, and works in the others.
"I've worked on my changeup a lot," he said. "It's getting a lot better. Now I'm just working on throwing my breaking ball not just to one side but to both sides [of the plate]. That's been a big improvement for me. Being able to throw it to the other side, which would be my arm side, is a lot better, because it's almost unexpected because I never had to do that before."
Rzepczynski will stay with the team for now to work on a conditioning program, but he won't even be throwing on the side. Then next year he will try to further establish himself in what the Blue Jays hope is a healthier starting rotation.