After the end of World War II, Kaplowitz was released from the Army, and he returned to NYU to finish his degree in education.

[1] On November 1, 1946, in Toronto, Canada, the 27-year-old Kaplowitz appeared in the starting line-up of the very first game of NBA/BAA history, alongside fellow Knicks Ossie Schectman, Sonny Hertzberg, Jake Weber, and Leo Gottlieb.

Kaplowitz and his teammates, many of them Jews, recall an increased level of anti-Semitic heckling by fans at Madison Square Garden as the season progressed.

Halfway through the season, on January 16, 1947, the Knicks sold Kaplowitz to the Philadelphia Warriors,[2] which were then coached and owned by Eddie Gottlieb.

In a 1997 interview of the team, Hertzberg said that by the end of the 1946–47 season, he was only Jewish player left on the Knicks' roster, but even he was traded during the league's first off-season break.