A 6’1, 210-pounder from Yorba Linda who was a top-250 national prospect in the 2020 recruiting class, Guillemette was regarded as a solid defensive catching coming out of high school.
As a freshman at USC, Guillemette stepped into the starting role and hit .299 with 10 doubles and three home runs, showing impressive contact ability at the plate, striking out on only 18.3 percent of his at bats.
Guillemette kept the starting role as a sophomore, batting .286 with 10 doubles and five home runs while maintaining his low strikeout rate.
With Silas Ardoin expected to move on to professional baseball, Guillemette will compete with rising junior Kimble Schuessler and incoming freshman Rylan Galvan for the starting job. Guillemette arguably becomes the favorite to win it, providing a potential bridge to Galvan in 2024, who is also well regarded as a contact hitter and known as perhaps the best defensive catcher in the state of Texas. The ability to avoid strikeouts makes Guillemette a potential option at designated hitter if he loses the competition to become the starting catcher.