Career
Käsler had his greatest success as a player in the 1950s. In 1955 he led the German national team to a world championship in field handball. After his career as a player, he coached at Berlin University and wrote several manuals on training tactics and conditioning for the game.
On 1 October 1972, he succeeded Werner Vick as trainer of the German national team, a position he held until 1974.
