In 1972, McNally was named to the All-Star Game for the third time. He finished the year with his first losing record since 1964, though this was partly due to the Orioles scoring fewer runs than they had the previous year. In 1973 and 1974, he faced the Oakland Athletics in the playoffs but lost both games he pitched. Thinking he needed a change of scenery, McNally requested a trade after the 1974 season; the Orioles obliged, sending him to the Montreal Expos, with whom he played one final year before retiring halfway through 1975, citing an inability to throw the fastball. After the 1975 season, he added his name to a grievance filed against the reserve clause, which resulted in the historic Seitz decision that created free agency in baseball. McNally returned to his hometown Billings and worked as a car dealer until his death from cancer in 2002. A member of the Baltimore Orioles Hall of Fame, he is among the franchise's leaders in many statistical categories.