Career
Kellner, 6 feet (18 metres) tall and weighing 200 pounds (91 kg) during his career, batted and threw right-handed. Kellner signed with the Athletics as an amateur free agent in 1949. He started out with Lincoln in the Western League, winning three games and losing fourteen in his first pro season.
He served in the military in 1951 and part of 1952, but returned to baseball late in 1952 and debuted with Philadelphia on September 6 of that year.
In his very first game, he picked up a save, facing 19 batters over four innings pitched and giving up four hits and three runs. He played two more games the following year, allowing one hit and two runs over three innings.
Kellner played several more years in the minors before retiring in 1958. He died in his hometown of Tucson, Arizona, on June 19, 2006.
The two were teammates in 1952 and 1953.