Graduated from Rowlett (Texas) High School. Attended Grayson County College in Texas before transferring to University of Oklahoma. Was drafted three times. The Brewers selected Okert in the 43rd round of the 2010 draft while he was a starting pitcher at Grayson College in Grayson County, Texas. He declined to sign, and was returned to Grayson for the 2011 season. The Brewers selected him again in 2011, this time in the 33rd round. Okert again turned them down in order to continue his college career. In 2012, he transferred to the University of Oklahoma, where his draft stock would skyrocket…in his only season as a Sooner, he pitched primarily out of the bullpen, making 25 of 30 appearances as a reliever. In 85.0 innings, he posted a 9-8 record with 78 strikeouts and a 3.07 ERA. The Giants rewarded him by drafting him in the fourth round in 2012. Involved with the following organizations: Little League Support.
Was recalled from triple-A Sacramento to the big leagues on four different occasions and went 1-1 with a 5.67 ERA (17er, 27.0ip) in 44 relief appearances...His 11 holds ranked second on the club behind Hunter Strickland (21)...Earned his first career big league win on May 3 at Los Angeles-NL (1.2ip)...Went 3-0 with a 3.20 ERA (9er, 25.1ip) and six saves in 24 games with Sacramento.
Made three stints with the Giants and posted a 3.21 ERA (5er, 14.0ip) over 16 outings. Made his Major League debut on April 19 vs. Arizona and tossed 2.0-scoreless innings, allowing one hit with two strikeouts. Struck out 14 batters in 14.0 innings of work for San Francisco, while holding opponents scoreless in 13 of his 16 appearances. Went 4-3 with a 3.80 ERA (20er, 47.1ip) and 60 Ks in 41 games for triple-A Sacramento.
Spent all of the 2015 season pitching out of the Sacramento River Cats' bullpen, fashioning a 3.82 ERA witih 69 strikeouts in 61.1 innings pitched over 52 appearances...held left-handed batters to a .228 average against....Was added to the Giants' 40-man roster on November 20, 2015.
Posted the best season of his professional career, being named an Organizational All-Star by MILB.com. Combined for 57 games with Class A Advanced San Jose and double-A Richmond, going 2-2 with a 2.11 ERA and 24 saves. His 24 saves led the entire Giants' organization, more than even Santiago Casilla and Sergio Romo. Began the year with San Jose and racked up 19 saves with a 1.53 ERA (6er, 35.1ip) and 54 strikeouts. Was named to the California League mid-season All-Star team and earned the save with a scoreless 9th inning. Was promoted to double-A Richmond on June 24 and went 1-0 with a 2.73 ERA (10er, 33.0ip) and five saves in 24 games. Posted a 0.75 ERA (1er, 12.0ip) with 17 Ks and a save in 10 games with the Scottsdale Scorpions in the Arizona Fall League. Was selected to the AFL All-Prospect Team and was named a Rising Star in the Arizona Fall League.