While his Major League teammates were getting ready to face the Tigers, McGuire was in Clearwater, Fla., making his unofficial debut in a "B" game against Philadelphia.
It marked the first opportunity for the 11th overall pick from the 2010 First-Year Player Draft to showcase his skills in front of Toronto's brass.
"It has been a long time coming, but it was great to get the first one out of the way," said McGuire, who signed for a $2 million bonus just before the Aug. 16 deadline. "I felt pretty nervous in the bullpen, but once I got on the mound and threw a couple of pitches I felt great."
McGuire caught the attention of Blue Jays scouting director Andrew Tinnish while pitching at the NCAA level. During his three years with Georgia Tech, McGuire went 28-7 with a 3.28 ERA and 306 strikeouts over 291 innings.
2010 Spring Training - null
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In his freshman year, he led the club in victories before breaking out in 2009. That year, he went 11-2 with a 3.50 ERA and 118 strikeouts over 100 1/3 innings. McGuire's win total tied for 10th in school history and he became the first Yellow Jackets hurler to be named the Atlantic Coast Conference Pitcher of the Year.
The 21-year-old is more advanced than most pitchers who are attending their first Major League Spring Training. His experience in a tough conference and his impressive arsenal of pitches seem to indicate he will be able to advance through the Minor Leagues at a relatively quick rate.
Blue Jays manager John Farrell isn't about to put any timelines on his young starter's ascension, though. McGuire is expected to begin the year with either Class A Lansing or Class A Dunedin, and the club will wait to see how he adjusts before making any other decisions.
"The fact remains that he'll be getting the ball every five days and going out to establish a consistent work outline," Farrell said. "Understanding what 28, 29 starts over the course of a Minor League season will do -- will require from him physically. That's really the goal in Year One, establishing that routine that will take into account a full five-month season."
McGuire throws four different types of pitches. He throws a fastball in the low-to-mid 90s while his slider ranges from 82-85 mph. He also possesses a changeup that he describes as a "work in progress" and a curveball that he used to throw in the low 70s, but now throws slightly harder.
The curve and his cut fastball are the two areas that McGuire has been trying to improve the most this Spring.
"It has a tighter spin," McGuire said of his new curve. "It's really starting to come along ... I kind of lost it in my last year or two in college and didn't use it as much as I had in the past. I'm looking forward to throwing it more in my first full season."
In Saturday's "B" game, McGuire allowed one earned run on three hits and two strikeouts over two innings against the Phillies.
In the first frame, all three of his outs came on ground balls. It's impossible to take any final analysis from such a small sample size, but his ground-ball ratio is something that McGuire will continue to monitor as the season progresses.
"I was known a little bit as a fly-ball pitcher in college," McGuire said. "Our thing here is to pound the ball down in the zone. No pun intended, but they pound it into our heads that that's what we have to do. So right now, I'm trying to get as many ground balls as I can and keep the ball out of the air."
Farrell didn't want to place too much importance on McGuire's debut. More than anything else he was impressed with the 6-6, 225-pounder's mental approach to the outing. McGuire was aggressive early in the count and didn't see to doubt his ability.
"The most important thing is that he didn't fear contact," Farrell said. "That's the most significant outward sign of what's taking place internally, is that he wasn't pitching away from guys and fearing contact.
"He hasn't pitched against a wood bat for very long. A lot of times, you get guys coming out of college that as they face the aluminum bat and you pitch to swing and miss and that hasn't been the case."
McGuire said that type of approach was easy to take after he took a look around at players he will eventually be facing this season in the Minors. Some of his future opponents he already had experience throwing to in college.
"Baseball's all about confidence," McGuire said. "At Georgia Tech, I faced some of the best hitters that are in the Minor Leagues right now, and some of the best competition for three years. It really helped build my confidence and give me the idea I can play with anybody, I can pitch against anybody on any given day."