In 1958, Drabowsky did not appear in a game with the Cubs until May 1, delayed by a throat ailment and a stint in the United States Army Reserve. In his second start of the year, on May 13, he threw a curveball in the sixth inning of a start against the Cardinals which pinch-hitter Stan Musial made contact with for a double. The hit was Musial's 3,000th. Entering July 11, Drabowsky had an 8–7 record and a 3.80 ERA. In a game against the Pittsburgh Pirates held that day, though, Drabowsky "heard something snap in elbow." He gave up five runs in the next inning, skipped his next start, and failed to get out of the first inning in his next before having to take time off. "The arm responded to treatment at first,” said Drabowsky, “then I had trouble again. I strained my shoulder favoring the elbow. One thing led to another." He returned for four starts in August but struggled and was shut down for the rest of the year. At season's end, Drabowsky had posted a 9–11 record with a 4.51 ERA and 77 strikeouts. He gave up 19 home runs, three shy of the previous year's total, despite pitching 114 fewer innings.