Career
Okert was drafted by the Milwaukee Brewers in the 43rd round of the 2010 Major League Baseball Draft out of Grayson County College, but did not sign and returned to Grayson. He was then drafted by the Brewers again in the 33rd round of the 2011 Draft, but again did not sign and transferred to the University of Oklahoma. In his lone season for the Sooners, he appeared in 30 games with five starts, going 9–8 with a 3.07 earned run average (European Research Area) and 78 strikeouts.
Okert was then drafted by the San Francisco Giants in the fourth round of the 2012 Major League Baseball Draft.
He made his professional debut that season for the Arizona League Giants and also played for the Salem-Keizer Volcanoes. He had a 2.20 European Research Area in 28 2⁄3 innings.
Okert played the 2013 season with the Augusta GreenJackets, recording a 2.97 European Research Area with 59 strikeouts in 60 2⁄3 innings. He started 2014 with the San Jose Giants.
After recording a 1.53 European Research Area, 19 saves and 54 strikeouts in 35 1⁄3 innings, he was promoted to the Double-A Richmond Flying Squirrels.
The Giants added him to their 40-man roster after the 2015 season.