Danny Darwin arrived in the Houston organization via a mid-1986 trade from Milwaukee, providing an immediate spark for the division-winning "Mike Scott Era" staff. Known by the chilling nickname "Dr. Death" for his intense competitive fire and willingness to protect his teammates, Darwin spent six seasons in the Space City across two different stints.

The best season of Darwin’s Astros run was in 1990.  That summer, he demonstrated a specialized ability to dominate in any capacity, appearing in 48 games but making only 17 starts. He showed the organization he was a foundational ace by leading the National League with a 2.21 ERA and a major league-best 1.027 WHIP, making him the third Astro in five years to claim the league's ERA crown. This specialized "swingman" dominance earned him the 1990 Houston Astros MVP award.

His first tenure was defined by high-frequency reliability; between 1986 and 1990, he provided the club with nearly 700 innings of quality work while primarily neutralizing right-handed hitters. After leaving for a four-year contract in Boston, everything culminated in a brief, nostalgic return in 1996. Acquired from the Pirates in a July trade, the 40-year-old veteran showed the organization he was still a professional by helping the club during the final two months of the season, recording his final three wins in a Houston uniform to finish his Astros career with a combined 47-35 record.