Willis was wild and ineffective when he came up with the Cincinnati Reds in 1984. He failed to improve, walking 32 men in 52 innings in 1986, and was demoted to the minors. The Reds gave up on him two years later, and shipped him to the Chicago White Sox.
Willis bounced between four organizations between 1988 and 1991, throwing a combined 12 big-league innings in that span. However, he found his niche with the Minnesota Twins in ’91, becoming the primary setup man for closer Rick Aguilera. He posted a 15-6 record with three saves and a stellar 2.67 ERA during the ’91 and ’92 seasons.
Willis’ newfound success came from dramatically improved control. He walked only 30 batters in 158 1/3 innings during those first two seasons as a Twin. Willis rang up another solid season in 1993, but became hittable in ’94, allowing 89 hits in just 58 innings.