Jason Frasor, 5.1 fWAR
Jason Frasor made his major league debut in 2004 and worked out of the bullpen for his entire career. He spent most of his career with the Blue Jays, accumulating a 5.1 fWAR over 504 2/3 innings, the third-most relief innings in team history. His 505 appearances are the most by any Jays pitcher.
The former 33rd-round pick made an impact in his first season in Toronto, emerging as a go-to saves option in an otherwise forgettable bullpen on a 67-94 Jays team. He secured 17 saves in 19 opportunities.
Frasor learned to throw a split-finger fastball in his rookie year because he had trouble spinning the ball after three elbow surgeries, including two Tommy John procedures, per David Laurila of FanGraphs.
Frasor's splitter, which he called a changeup, became his secondary pitch for the rest of his career. Whatever it was, it worked for him, and his 83 holds still stand as the second-most in franchise history.
The Illinois native had his most valuable season with the Blue Jays and his career in 2009. He made 61 appearances, striking out 56 batters in 57 2/3 innings, with a 2.50 ERA. He recorded 11 saves and four holds and earned a 1.4 fWAR for his efforts.
After seven seasons plying his trade out of the Toronto bullpen, the team traded him to the Chicago White Sox during the 2011 season. The White Sox promptly returned him in the offseason, and he spent one more season in a Blue Jays uniform in 2012. He finished his Blue Jays career with a 3.73 ERA, a 25-29 record, 36 saves and 479 strikeouts, the third-most among Toronto relievers.
Frasor pitched for three more years, splitting time between the Texas Rangers, Kansas City Royals and Atlanta Braves. He even helped the Royals make it to the World Series in 2014.
Next: This reliever's only postseason save is the biggest in team history