4. Jimmy Key
Jimmy Key is one of the most consistent pitchers the Blue Jays have had. He didn’t blow hitters away, but he didn’t walk many either, and the southpaw kept the ball in the ballpark. When Key was first called up in 1984 he was used exclusively as a reliever. Once the Jays took the training wheels off the following season and let Key start games, he made an immediate impact. His 141 ERA+ was fourth in the American League and he was an All-Star.
In the 1987 season, Key led the American League with a 2.76 ERA. He went 17-8 in 36 starts and 261 innings pitched. He led the league with a 164 ERA+ and a 1.057 WHIP. He ended up finishing second in the American League Cy Young race behind Roger Clemens. Key being this dominant while only striking out 5.6/9 is impressive.
Key was outstanding in the 1992 postseason for the Jays. In his one appearance in the ALCS, he delivered three shutout innings in a win. In his lone World Series start, he went 7.2 innings allowing just one run on five hits, with no walks and six strikeouts in a 2-1 Jays win that put them up 3-1 in the series.
Key would then come out of the bullpen just two days later and pitch in the decisive Game 6. He tossed 1.1 innings allowing an unearned run. He ended up being the winning pitcher in the series clincher.
Key did not throw hard and did not strike out many hitters, but he was extremely effective in his nine years in Toronto, including on the biggest stage. He ranks third in bWAR for pitchers, third in ERA (first for starting pitchers), fourth in innings pitched, and second in WHIP.