In 1967, McNally was the Opening Day starter for Baltimore. He was throwing a shutout against the Angels in the first game of a doubleheader on April 16, 1967, but he allowed two runs in the eighth inning. In the ninth, with the Orioles up 4–2, McNally retired the first two Angel hitters he faced but surrendered the lead when he gave up back-to-back home runs to José Cardenal and Don Mincher. He was removed from the game, and the Orioles lost 5–4 in 10 innings. After losing just six games in 1965 and 1966, McNally had five losses through June 18 of 1967, with a 5.71 ERA to go along with them. In June, doctors discovered a calcium deposit in his left elbow. They treated the injury through draining fluid and injecting cortisone. Following his first cortisone shot, McNally limited the Chicago White Sox to one run and five hits on July 6 in a complete-game, 5–1 victory. One week later, in the second game of a doubleheader against the Boston Red Sox, he threw a shutout as the Orioles won 10–0. However, the injury restricted him to four games after July 21. In 24 games (22 starts), he had a 7–7 record, a 4.54 ERA, 70 strikeouts, 39 walks, and 134 hits allowed in 119 innings.