Pearson was considered one of the top prospects for the 2017 Major League Baseball draft.[4][5] He was selected 28th overall by the Toronto Blue Jays,[6][7] and signed on June 28 for a $2.45 million bonus.[8][9] Pearson was assigned to the Rookie-levelGulf Coast League Blue Jays, and promoted to the Short Season-AVancouver Canadians after making one start.[10] Through his first six starts, Pearson did not allow a run, and yielded only four hits and one walk while striking out 16 in 13 total innings.[11] He finished the 2017 regular season with a 0.90 ERA, 26 strikeouts, and a 0.60 WHIP in 20 innings pitched.[10] In early September, Pearson was selected by Vancouver as the starter for the first game of their best-of-three Northwest League playoff series against the Spokane Indians.[12][13] He went four innings against Spokane and struck out 10 batters in a 2–1 win.[14]
Pearson was assigned to the Advanced-ADunedin Blue Jays to begin the 2018 season, but opened the year on the disabled list with an oblique injury. He made his Florida State League debut on May 7, but left the game after being struck by a line drive in the second inning. The following day, the team announced Pearson had suffered a broken ulna in his right arm.[15] He remained on the disabled list for the rest of the 2018 season, and played for the Surprise Saguaros of the Arizona Fall League during the offseason. Pearson began 2019 with Dunedin, where he posted a 3–0 record, 0.86 ERA, and 35 strikeouts in 21 innings pitched before being promoted to the Double-ANew Hampshire Fisher Cats in early May. He made his Double-A debut on May 7, striking out eight over five scoreless innings.[16] Pearson was named to the 2019 All-Star Futures Game.[17] Pearson was assigned to Triple-A Buffalo on May 3, 2021.[18]
On July 29, 2020, Pearson made his MLB debut against Max Scherzer and the Washington Nationals. The game was played in Washington despite being a home game for the Blue Jays, as the COVID-19 pandemic had forced the Blue Jays into Sahlen Field in Buffalo, which was not ready for use.[19] He went five innings, giving up two hits and two walks with five strikeouts, and surrendered no runs in his debut, though the Nationals won 4–0.[20][21] With the 2020 Toronto Blue Jays, Pearson appeared in 5 games, compiling a 1–0 record with 6.00 ERA and 16 strikeouts in 18 innings pitched.[22]
Pearson made 12 appearances for Toronto in 2021, posting a 1–1 record and 4.20 ERA with 20 strikeouts in 15.0 innings pitched. On June 6, 2022, Pearson was placed on the 60-day injured list.[23] On June 24, Pearson was diagnosed with a lat strain.[24] He did not appear in the major leagues for Toronto in 2022.
Pearson was optioned to the Triple-A Buffalo Bisons to begin the 2023 season,[25] and pitched out of the bullpen. In 81⁄3 innings, Pearson recorded a 2.16 ERA and 16 strikeouts. On April 24, he was recalled to the major leagues.[26]
