A left-handed pitcher, Dravecky represented the Padres at the All-Star game in 1983, his second season, in which he won 14 games. Equally proficient as a starting pitcher or coming out of the bullpen, Dravecky helped the Padres to their first pennant the following year.
In 1987, the San Francisco Giants acquired Dravecky for their pennant drive. He went 7-5 during the stretch, and in the playoffs pitched a shutout in Game 2 against the St. Louis Cardinals and lost Game 6 by a score of 1-0. The Cards won in seven games.
The following season, a cancerous tumor was found in Dravecky's pitching arm. He underwent surgery on October 7, 1988, removing half of the deltoid muscle in his pitching arm and freezing the humerus bone in an effort to eliminate all of the cancerous cells. By July of 1989, he was pitching in the minor leagues, and on August 10, he made a highly publicized return to the major leagues, pitching 8 innings and defeating the Cincinnati Reds 4-3. In his following start five days later against the Montreal Expos, Dravecky pitched three no-hit innings, but in the fifth inning, he felt a tingling sensation in his arm. In the sixth inning, he gave up a home run to the leadoff batter, hit the second batter, and in his first pitch to Tim Raines, his humerus bone snapped, ending his season.
The Giants won the National League pennant in 1989, and in the post-game celebration, Dravecky's arm was broken a second time. A doctor examining Dravecky's x-rays noticed a mass in his arm. Cancer had returned. Eighteen days later, Dravecky retired from baseball, aged 33, with a career record of 64-57 and a career ERA of 3.13 in 8 seasons.
Dravecky wrote two books about his battles with cancer and his comeback attempt: Comeback, published in 1990, and When You Can't Come Back, published in 1992.