Pittsburgh Pirates (2013–2016) in 2015 As a high school catcher,
Major League Baseball (MLB) analysts praised McGuire's defensive ability, and analysts projected he would be taken in the first round of the
2013 MLB draft. At the time, McGuire had committed to play
college baseball for the
San Diego Toreros. He signed with the Pirates on June 18, earning a $2.36 million
signing bonus in the process, and was assigned to the
Rookie-level GCL Pirates. In his
professional baseball debut on July 4, McGuire recorded four
hits, three RBI, and two
doubles. After hitting .330 with 11 doubles and 21 RBI in 46
Gulf Coast League games, McGuire was promoted to the
Class A Short Season Jamestown Jammers at the end of August. He appeared in only four
New York–Penn League games, going 4-for-16 with a
walk in the process. McGuire was one of several highly regarded prospects to join the
Low-A West Virginia Power for the 2014 season. As a
South Atlantic League prospect, McGuire demonstrated at 1.8-second
pop time behind the plate, as well as consistent contact hitting. Batting .277 with one home run and 19 RBI through the midway point of the season, including a 19-game hitting streak in May, McGuire was named a South Atlantic League All-Star. He finished the season batting .262 with three home runs and 45 RBI in 98 games. McGuire opened the 2015 season with the
High-A Bradenton Marauders of the
Florida State League (FSL). After hitting .259 to start the season, with 10
stolen bases and throwing out 14 opposing base stealers, McGuire was named an FSL All-Star in June. He finished the season batting .254 with 15 doubles and 34 RBI. McGuire was one of 12 Pirates prospects invited to attend
spring training with the team in 2016. After being reassigned to minor league camp in March, he opened the season with the
Double-A Altoona Curve. One of the youngest players on the team, McGuire showed more consistency and discipline at the plate, drawing walks and keeping his batting average above .250, although he still lacked power. In 266 at bats across 77 games, he hit .259 with one home run and 37 RBI. He finished out the season with the Double-A
New Hampshire Fisher Cats, batting .226 with five RBI in 15 games and 53 at bats. After suffering the knee injury in early May, McGuire was able to return to Double-A at the start of August, and shortly after his return, McGuire's home runs in three consecutive games earned him
Eastern League Player of the Week honors for the week ending August 20. In his limited appearances in 2017, McGuire batted .295 with six home runs and 28 RBI in 149 at bats. He played for the
Buffalo Bisons of the
Triple-A International League in 2018. On September 6, 2018, the Blue Jays promoted McGuire to the major leagues. He made his MLB debut that night against the
Cleveland Indians and hit a double in the game for his first career hit. He hit his first career home run on September 26 against the
Houston Astros. In 14 major-league games, McGuire batted .290 with two home runs and four RBIs. McGuire joined the Blue Jays in late July after
Luke Maile was injured, and appeared in 30 games throughout the season, hitting .299 with an .872 OPS. Overall with the
2020 Blue Jays, McGuire batted .073 with one home run and one RBI in 19 games. On April 1, 2021, McGuire was
designated for assignment by the Blue Jays. Clearing waivers, he was assigned to the Jays' alternate training site, McGuire played in 53 games for Chicago, batting .225 with no home runs and 10 RBIs. McGuire played 36 games for the Red Sox in 2022, batting .337 with three home runs and 12 RBI. On January 13, 2023, the Red Sox and McGuire reached agreement on a one-year contract, avoiding salary arbitration. He served as Boston's backup catcher until June 22, when he was placed on the
injured list with a right
oblique strain. McGuire was activated on August 1, and hit his first home run of the season later that day. In 72 total appearances, he slashed .267/.310/.358 with one home run and 16 RBI. On January 12, 2024, McGuire once again avoided salary arbitration with the Red Sox by signing a one-year contract with the team. On April 7, McGuire drove in a career high of five RBI in a 12–2 victory over the
Los Angeles Angels. On July 28, McGuire was designated for assignment by the Red Sox. In 52 games for Boston, he batted .209/.280/.295 with three home runs and 18 RBI. Red Sox manager
Alex Cora explained that the team made a change at the backup catcher position in consideration of roster balance, changing from a left-handed batter (McGuire) to a right-handed batter (
Danny Jansen). McGuire cleared waivers and was sent outright to the Triple–A
Worcester Red Sox on August 2. He elected free agency on September 30.
Chicago Cubs (2025) On January 22, 2025, McGuire signed a minor league contract with the
Chicago Cubs. In 22 appearances for the Triple-A
Iowa Cubs, he batted .280/.360/.467 with three home runs, 19 RBI, and two stolen bases. On May 25, the Cubs selected McGuire's contract, adding him to their active roster. In his first plate appearance for the Cubs that day, he hit a solo home run, following it up later in the game with a game-tying solo home run, ultimately resulting in a Cubs comeback victory. McGuire made 44 appearances for the Cubs, batting .226/.245/.444 with nine home runs and 24 RBI. On November 21, he was non-tendered by Chicago and became a free agent.
Chicago White Sox (second stint) On January 28, 2026, McGuire signed a minor league contract with the
Milwaukee Brewers. He opted out of his contract with the Brewers on March 21 after being told he would not make the major league roster. On March 22, McGuire signed with the
Chicago White Sox on a one-year, $1.2 million contract. He made 11 appearances for Chicago, going 5-for-29 (.172) with three RBI and two walks. On April 25, McGuire was designated for assignment by the White Sox following the promotion of
Drew Romo. ==Personal life==