Donald was the Yankees’ number-four or -five starter for most of his career. He was blessed with the support of New York’s tremendous offense and sparkling defense, but was also a good pitcher in his own right. His only losing record, 0-1, came in his two-game call-up in his first season, 1938. In 1939 he was 13-3 with a 3.71 ERA that was nearly a run lower than the league average. His 3.03 ERA in 1940 would have been the third-best in the AL had he been used enough to qualify. He continued to pitch effectively until 1945, when eye and elbow injuries ended his career.
In his only World Series start, Game Four of the 1941 WS, Donald took a no-decision, surrendering four runs in four innings. Nonetheless, the Yankees took a 3-1 Series lead when the Dodgers Mickey Owen committed his famous passed ball in the ninth inning, allowing a Yankee rally to erupt. Donald took a loss in relief in Game Four of the 1942 Series as the Cardinals handed the Yankees their first losing World Series in 20 years.