The Astros had never had a good all-around shortstop until the arrival of Dickie Thon. Acquired before the 1981 season for pitcher Ken Forsch, the Indianan began to show promise in the 1982 season with a league-high ten triples and a career-best 37 steals. The following season, he added another dimension to his game, slugging 20 homers and earning a spot on the NL All-Star team with a .286 average and 34 steals.

Thon was off to another fine start in the first week of the 1984 season when his career was derailed. Facing the New York Mets, Thon was struck in the temple by a high fastball from Mike Torrez. Thon fell to the ground bleeding, his season suddenly over. Contending with headaches, blurred vision, and nausea, Thon was unable to return to action until midway through the 1985 season. The injury continued to hamper him through two more seasons of part-time play with the Astros. Over seven seasons in Houston, he had a .270 average with 33 homers and 94 steals.

He did not return to an everyday role until 1989, when he hit .271 with 15 homers for Philadelphia. After two more seasons with the Phillies and another two in the American League with Texas and Milwaukee, Thon retired at age 35. In his 15 seasons in the majors, he compiled a .264 average with 71 homers and 167 steals.