Juan Guzman signed with the Los Angeles Dodgers as an Amateur Free Agent in 1985, but two years later, while still in the low Minors, he was traded to the Toronto Blue Jays.  He finally made his way up to the Majors in 1991, where he went 10-3 and was a distant second to Minnesota's Chuck Knoblauch.

Over the next two seasons, Guzman was part of an electrifying team that won the 1992 and 1993 World Series Championships, and he went 30-8 over that time.  Guzman finished seventh in Cy Young voting, and it looked like it was the start of something special for the Pitcher, but it was not to be.

Guzman struggled in 1994 and 1995, posting ERAs of 5.68 and 6.32, respectively, with WHIPs over 1.6.  It looked like it might be over for Guzman, but he rebounded in 1996, winning the ERA Title (2.93) while also leading the AL in ERA+ (171), WHIP (1.124), H/9 (7.6) and SO/BB (3.11).  Amazingly, he did not receive any Cy Young votes.

Guzman struggled again the year after and was traded mid-season to Baltimore.  With the Blue Jays, Guzman went 76 and 62 with 1,030 Strikeouts.