Before the start of the 1961 baseball season, which ended with the Yankees' 19th World Series title, LIFE Magazine gave a camera to 25-year-old Yankee shortstop Tony Kubek and asked him to take portraits of his teammates. He shot Mickey Mantle, Yogi Berra, Roger Maris, Whitey Ford, and others at the team's spring training field.

The photos have never been published before, partly because LIFE photographer Bob Fellows—a self-described "baseball hater"—was unhappy with the results. In a letter dated March 13, 1961, he wrote to the LIFE offices with the two rolls of film, which he referred to as the "pitiful results of three lost days." has a gallery of the shots up now. Above: Berra poses with his book, while Kubek and Maris set up a shot. Go check it out.

NEVER-SEEN: '61 Yankees Goofing Off []