Originally drafted as a standard, overhand starting pitcher, he made a brief big-league debut in 1982 before severe shoulder issues completely derailed his career. Facing an early retirement, Eichhorn reinvented himself out of sheer survival, dropping his arm slot down to a deceptive, frisbee-like sidearm delivery. That mechanical overhaul completely changed his life. When he finally returned to the majors in 1986 after a four-year absence, he didn't just survive—he authored one of the most dominant, high-volume relief seasons in the sport's history.
That 1986 campaign was an absolute masterpiece of bullpen efficiency. Relying on an unhittable, changing-speed changeup and a sinking fastball that defied gravity from his low arm angle, Eichhorn paralyzed American League hitters. He made 69 appearances, swallowed up a jaw-dropping 157.0 innings strictly in relief, and compiled an incredible 14–6 record with a microscopic 1.72 ERA. He was an absolute workhorse, backing up that rookie showcase by leading the entire American League with a staggering 89 pitching appearances in 1987. Across a three-year span, his rubber arm racked up 24 wins out of the bullpen, making him an absolute favorite of the Exhibition Stadium faithful.
As the front office retooled the roster, Toronto sold his contract to the Atlanta Braves in 1989. Eichhorn eventually found his groove again with the California Angels, which set the stage for a dramatic, full-circle homecoming. In August 1992, the Blue Jays traded for their former bullpen star to reinforce their late-inning bridge for the stretch run.
His second tour in Toronto was defined by calm, veteran precision. Operating as a steady middle-relief specialist, Eichhorn became a vital, high-leverage cog in the machine that secured the franchise's back-to-back world championships. He turned in a tidy 2.38 ERA down the stretch in 1992 and followed it up by throwing 45 crucial games with a 2.72 ERA during the historic 1993 title defense, giving Cito Gaston total structural reliability ahead of closer Duane Ward.
Following the 1993 triumph, Eichhorn departed as a free agent to sign with Baltimore, eventually wrapping up his 11-year major league journey with a stop in Anaheim. Over his two stints in Toronto, Eichorn appeared in 279 games (only 7 starts) with a 31–22 record, a 3.03 ERA, and a 1.15 WHIP. He worked 481.1 innings, recording 14 saves and 338 strikeouts while generating an elite 139 ERA+.