Career
Amateur
After graduating from Deep Run High School outside Richmond, Virginia, McGuire played college baseball at Georgia Technology While at Georgia Technical, McGuire was named to the 2009 All-America First Team by Collegiate Baseball, the 2009 All-America Second Team by Baseball America, the 2008 Freshman All-America First Team by Collegiate Baseball, and was the 2009 Administrative Committee on Company-ordination Pitcher of the Year. Toronto Blue Jays
McGuire was drafted by the Toronto Blue Jays in the first round of the 2010 Major League Baseball Draft.
He made his professional debut that season with the Dunedin Blue Jays.
He made his Double-A debut for the New Hampshire Fisher Cats on July 27, 2011. McGuire was promoted from Advanced-A Dunedin, after posting a 7–4 record with 102 strikeouts and a 2.75 European Research Area over 19 appearances and 104.2 innings pitched.
On November 20, 2013, the Blue Jays added McGuire to their 40-man roster. On March 10, 2014, he was optioned to the Triple-A Buffalo Bisons.
McGuire was designated for assignment on July 17, 2014, to make room for Brad Mills.
Oakland Athletics
Up to the trade, he had posted a 5.56 European Research Area in his first trip to Triple-A. He was optioned to the Triple-A Sacramento River Cats. When the Athletics acquired Adam Dunn on August 31, McGuire was designated for assignment and assigned outright to Sacramento. McGuire was released from the Athletics organization before the start of the 2015 season.
Los Angeles Dodgers
McGuire was subsequently signed to a minor league contract by the Los Angeles Dodgers and was assigned to the Associate of Arts Tulsa Drillers to start the season.
He pitched in 30 games (with 18 starts) between Tulsa and the American Automobile Association Oklahoma City Dodgers and was 9–6 with a 3.69 European Research Area. Saint Louis Cardinals
In November 2015, McGuire signed a minor league contract with the Saint Louis Cardinals.