After a standout college career at Miami University, where he was named CCHA rookie of the year in 2005-06 after going 14-5-1 with a 2.02 goals-against average, .928 save percentage and three shutouts, it took Zatkoff quite a while to make his NHL debut.
Zatkoff was selected by the Los Angeles Kings in the third round (No. 74) of the 2006 NHL Draft, but didn't make his first NHL start until the 2013-14 season. Zatkoff spent one season with the Ontario in the ECHL before playing four seasons with the Kings' American Hockey League affiliate in Manchester, increasing his wins total in each season. He was 21-17-1 with a 2.49 GAA, .920 save percentage and three shutouts in 2011-12 season.