Grasso had played only one season in the minor leagues when he enlisted in the United States Army in January 1942,[2] six weeks after the Attack on Pearl Harbor.

In the waning days of the war, in April 1945, as he was being marched westward by his captors, Grasso was one of ten allied prisoners who escaped German custody and the invading Soviet Red Army and was rescued by American troops.

Although he had lost 60 pounds (27 kg) during his internment, Grasso was able to return to professional baseball in 1946[1] when he played 106 games at the Triple-A level before his recall by the New York Giants in September.

After four seasons in Washington, Grasso was traded to the contending Cleveland Indians in January 1954, but a broken ankle sustained during spring training sidelined him until September 2.

Relieving regular catcher Jim Hegan in the tenth frame with the game tied 2–2, Grasso was behind the plate when Dusty Rhodes hit a walk-off, three-run homer off Indians' ace Bob Lemon.