Shantz graduated from Pottstown High School in Pottstown, Pennsylvania, in 1943.[3] He signed with the Philadelphia Athletics as a free agent and made his MLB debut in 1949. In 1952, Shantz led the American League (AL) in wins (24) and won the AL Most Valuable Player Award.[2] In the process, he led the A's to a 79–75 record and fourth-place finish in the American League, their last winning season in Philadelphia. In a September 1952 game, Shantz's left wrist was broken after he was hit by a pitch thrown by Walt Masterson of the Senators.[4] The following season, Shantz injured his shoulder in a game against the Boston Red Sox.[5] Shantz saw only limited action for the rest of 1953 and pitched only eight innings in 1954.[6] After the 1954 season was complete, the Athletics were sold and moved to Kansas City for the 1955 season.
A highly skilled fielder, Shantz won eight consecutive Gold Glove Awards from 1957 to 1964 (American League, 1957–60; National League, 1961–64; in 1957 the award was rendered for both leagues). Shantz also was selected for the All-Star Game in 1951, 1952 and 1957.[2] In the fifth and final inning of the 1952 All Star Game, the left–handed Shantz exhibited his distinctive sidearm delivery and sharp curve and control and struck out three consecutive National League hitters: Whitey Lockman, Jackie Robinson and Stan Musial.
He is the brother of former Major League catcherBilly Shantz. He is married to Shirley Vogel, and they have four children, Bobby, born in 1954, followed by Kathy, Teddy, and Danny, born in 1965.[12]
As of August 2024, Shantz is the third-oldest living Major League player.[13] Following the death of Bill Harrington in January 2022, Shantz became the last surviving player who played under Connie Mack.[14]