Ryu, 32, is fresh off of winning the ERA title this past season, authoring a 2.32 mark after accepting his one-year qualifying offer to remain with the Los Angeles Dodgers. The left-hander finished runner-up in NL Cy Young voting, going 14-5 over 29 starts and becoming a first-time All-Star.
The 2019 campaign marked the first time Ryu threw more than 150 innings since 2014.
Meanwhile, Keuchel was held to 19 starts with the Atlanta Braves last year, failing to sign until midseason after rejecting the Houston Astros' qualifying offer last November. The 31-year-old posted a 3.75 ERA and 4.72 FIP over 112 2/3 innings. The Blue Jays reportedly showed interest in Keuchel last winter as well.
Toronto is also reportedly eyeing Josh Lindblom, reports Ben Nicholson-Smith of Sportsnet. The 32-year-old right-hander spent the 2019 season in the Korea Baseball Organization, posting a 2.50 ERA over 194 2/3 innings. Lindblom last appeared in the majors in 2017 as a reliever for the Pittsburgh Pirates.
The Blue Jays have been pursuing starting pitching since the beginning of the offseason and were reportedly interested in Jake Odorizzi and Kyle Gibson. Odorizzi wound up accepting his one-year, $17.8-million qualifying offer with the Minnesota Twins, while Gibson landed a three-year deal with the Texas Rangers.
Toronto's rotation ranked 24th in the majors by FanGraphs' WAR last year and will enter the 2020 campaign without Marcus Stroman and Aaron Sanchez who, despite being traded midseason, ranked first and third in team WAR, respectively.