OFFICIAL: We’ve agreed to terms with International Free Agent RHP Seojun Moon!
Blue Jays officially ink Korean teenager Seojun Moon

Photo credit: Nathan Ray Seebeck-USA TODAY Sports
By Thomas Hall
Sep 25, 2025, 11:30 EDTUpdated: Sep 25, 2025, 11:31 EDT
The Toronto Blue Jays officially welcomed their newest international free agent signee to the organization on Wednesday, putting pen to paper with teenage right-hander Seojun Moon.
The 18-year-old, who’s the first Korean-born international signing in franchise history, reportedly agreed to a handshake deal with the Blue Jays over the summer, receiving a signing bonus of $1.5 million, as first reported by Spanish reporter Francys Romero.
Acquiring Moon was made possible, of course, by the $2 million in international signing bonus money that Toronto received from the Cleveland Guardians via last off-season’s Myles Straw trade.
The two players met for the first time on the field at Rogers Centre prior to Wednesday’s contest versus the Boston Red Sox, creating a full-circle moment for the forever-connected duo.
Myles Straw 🤝 Seojun Moon
Originally, the Blue Jays had acquired that bonus pool space to continue their pursuit of Japanese free agent Roki Sasaki, who ultimately signed with the Los Angeles Dodgers. Straw, meanwhile, has worked out better than anyone could’ve hoped in Toronto, posting a 1.7 fWAR over 133 games this season.
What was previously perceived as a huge swing and miss by the organization has since morphed into a major win-win. That’s some pretty tidy work by general manager Ross Atkins and the rest of the front office.
Moon immediately becomes one of the Blue Jays’ top pitching prospects after posting a 2.18 ERA with 93 strikeouts across 66 innings as a high schooler, logging 24 consecutive games without surrendering a home run. The 6-foot-4, 214-pound hurler opted for international free agency rather than entering the KBO draft.
He features a mid-90s fastball capable of touching 95 m.p.h., mixing in his slider (his primary swing-and-miss weapon), curveball and changeup.
The Blue Jays have yet to announce where Moon will begin his professional career in 2026. But he’ll likely start with the organization’s Florida Complex League affiliate, which is coming off its first-ever league championship victory.
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