Jonatan Clase Bio
Jonatan Clase (born May 23, 2002) is a Dominican professional baseball outfielder for the Toronto Blue Jays of Major League Baseball (MLB). He has previously played in MLB for the Seattle Mariners. Clase is widely recognized for his rare combination of speed and power, a skill set that pushed him quickly through the minor leagues and into the majors.
After signing as an international free agent in 2018, Clase worked his way up through several levels of Seattle’s farm system before reaching Triple-A. He made his MLB debut in 2024, split that season between Seattle and Toronto, and has since been a depth outfielder and speed threat in the Blue Jays organization.
Early Life and Background
Jonatan Clase was born on May 23, 2002, and grew up in the Dominican Republic, a country that has produced a long line of Major League Baseball stars. Like many Dominican prospects, Clase grew up around the game and developed his athletic profile through informal and organized baseball from a young age.
As a teenager, Clase drew attention from international scouts with his quick hands, speed on the base paths, and the raw power that would later define his professional profile. His signing on July 2, 2018, the opening day of the international signing period, marked the formal start of his professional career.
Path to Baseball
Clase began his professional journey in the Dominican Summer League in 2019, getting his first taste of full-season baseball as a teenager. The 2020 season was lost to the cancellation of the minor league schedule during the COVID-19 pandemic, a pause that delayed his development but did not derail it.
When play resumed in 2021, Clase appeared with the rookie-level Arizona Complex League Mariners, where a broken ankle cost him time but did not stop him from posting a .245 batting average with 16 stolen bases. His stock rose sharply in 2022 with the Single-A Modesto Nuts, when he hit 13 home runs and stole 55 bases, a performance that convinced Seattle to protect him on the 40-man roster ahead of the 2022 Rule 5 draft.
Jonatan Clase Career
Early Career (2019–2022)
Clase’s early professional years were spent moving through the lower levels of the Mariners organization while refining his approach at the plate. In 2022, at Single-A Modesto, he produced one of his first breakout stat lines, slashing .267/.374/.463 with 13 home runs, 49 RBI, and 55 stolen bases, numbers that confirmed he could both hit for power and run the bases at an elite rate.
That November 15, 2022, the Mariners added Clase to their 40-man roster to shield him from the Rule 5 draft, a clear sign the organization viewed him as a legitimate big-league prospect. Through these developmental years he built the foundation for his later promotion.
Minor League Breakthrough (2023)
The 2023 season marked Clase’s loudest minor league statement. Splitting the year between High-A Everett and Double-A Arkansas, he played 129 games and batted .242/.353/.449 with 20 home runs, 68 RBI, and 79 stolen bases. That production made him the first minor league player since at least 1961 to combine 20 home runs and 70 stolen bases in a single season.
His strong year was capped by an appearance in the All-Star Futures Game, where top prospects from across the sport face off. During the same season, Clase also began working with former Mariners outfielder Franklin Gutiérrez on his outfield defense, an effort to round out a profile that had always been defined more by his bat and legs than by his glove.
Seattle Mariners Era (2024)
Clase opened the 2024 season with the Triple-A Tacoma Rainiers before getting the call to the majors on April 15, 2024, following an injury to outfielder Dominic Canzone. In his MLB debut that day, a win over the Cincinnati Reds, Clase recorded a single and an RBI in his first game.
Across three stints in the majors with Seattle, Clase batted .195 with one double and three stolen bases, serving mainly as a speed-and-defense option off the bench. On July 26, 2024, the Mariners traded Clase and Jacob Sharp to the Toronto Blue Jays in exchange for reliever Yimi García, ending his time in the Seattle organization.
Toronto Blue Jays Era (2024–Present)
Clase made an immediate impression after joining Toronto. In seven games with the Blue Jays to close out 2024, he went 7-for-20 (.350) with one home run and two RBI. Statcast also tracked him as one of the fastest base runners in MLB that season, tied for third-fastest in the majors.
In 2025, Clase was optioned to the Triple-A Buffalo Bisons to begin the year before rejoining Toronto in May to replace Alan Roden on the roster. On June 9, he hit his first home run of the season to tie the game in the ninth inning against the St. Louis Cardinals, a moment that highlighted his knack for timely hitting. He made 34 appearances for Toronto during the regular season, batting .210/.288/.300 with two home runs, nine RBI, and three stolen bases.
Driving Style and Strengths
Clase is best described as a speed-first outfielder whose value is amplified by emerging power. He tracks the ball well in the outfield thanks to his work with Franklin Gutiérrez, uses his legs to pressure defenses on the base paths, and has shown the ability to change a game with a single swing, including a game-tying home run in 2025 against the St. Louis Cardinals.
Notable Events and Milestones
His 2023 minor league season stands as his headline achievement, becoming the first player since at least 1961 with at least 20 home runs and 70 stolen bases in a single minor league campaign. His MLB debut single and RBI against Cincinnati in 2024 and his first home run of 2025 against St. Louis bookend his top-line career moments so far.
Jonatan Clase Career Wins
Clase’s win totals as a position player are tied to his on-base ability, baserunning, and run production across each level. His biggest win-producing stretch came in 2023 at High-A Everett and Double-A Arkansas, where his 20 home runs and 79 stolen bases directly fueled wins for his clubhouses.
Minor League Highlights
During his time in the Mariners system, Clase collected milestone victories including his 2022 Single-A Modesto campaign with 13 home runs and 55 stolen bases, and his 2023 combined run at Everett and Arkansas that included 20 home runs and 79 stolen bases. He was also selected for the 2023 All-Star Futures Game, a notable recognition of his prospect status.
Other Wins and Performances
Beyond his headline seasons, Clase posted a .245/.333/.388 line in 14 games for the Arizona Complex League Mariners in 2021 and contributed a .350 batting average in seven games after his mid-2024 trade to Toronto, performances that added to his track record as a difference-maker at every level he has played.
Jonatan Clase Family
Family Background and Racing Lineage
Public information about Jonatan Clase’s parents and extended family is limited. As a Dominican-born prospect, he followed the same international pathway that has produced many MLB players from the region, signing with Seattle on July 2, 2018, as a teenager out of the Dominican Republic.
Personal Life
Clase keeps his personal life largely private, and there are no publicly verified details regarding a spouse or children. He maintains a public presence on social media, including X at clasejonatan and Instagram at class.23, where fans can follow his career.
2025 Season Performance
Jonatan Clase’s 2025 season began with an option to the Triple-A Buffalo Bisons before a May promotion to Toronto, where he replaced Alan Roden on the roster. He delivered one of his biggest moments on June 9, hitting a game-tying ninth-inning home run against the St. Louis Cardinals to help secure a Blue Jays win.
Across 34 appearances with Toronto during the regular season, Clase batted .210/.288/.300 with two home runs, nine RBI, and three stolen bases. His season also included a bruised right knee after being hit by a pitch from Arizona Diamondbacks pitcher Brandon Pfaadt on June 17, which interrupted his rhythm at the plate.
Looking ahead, Clase’s profile as a fast, athletic outfielder with growing power continues to fit the Blue Jays’ need for bench speed and late-inning defense. If he can translate more of his Triple-A production into the majors, he has a clear path to a more consistent role in Toronto’s outfield picture.
