Veteran pitching coach Jason Dietrich was added to the Cal State Fullerton baseball coaching staff on July 7, 2012. Dietrich replaced departed Kirk Saarloos, who took a similar position at TCU on June 20 after two seasons with the Titans. In 2014, Dietrich took over as the recruiting coordinator for Vanderhook’s coaching staff. 

In his four seasons at Cal State Fullerton, Dietrich helped develop one of the best pitching staffs in Titans history. In his first season with the program, the 2013 Titans pitching staff set new single-season records at Fullerton including earned run average (2.47), fewest walks (86), walks per nine innings pitched (1.41), hits per nine innings pitched (7.59) and shutouts (11).

In 2014, the Titans staff shattered the earned run average record set the previous season, posting a miniscule 2.24 ERA. The Titans allowed 136 earned runs in 545.1 innings pitched, the second fewest amount in school history. Along with the best ERA in school history, the 2014 Titans pitching staff ranked near the top of the school record book in the following categories: lowest opponent batting average (4th, .234), fewest walks allowed per nine innings (2nd, 1.52), most shutouts (t2nd, 9), fewest hits (7th, 471), fewest runs (2nd, 136), fewest walks (2nd, 92) and fewest home runs allowed (2nd, 12).

Not to be outdone, the 2016 Titans again broke the program’s ERA record, posting a 2.22 mark to lead the nation. The staff also set new Fullerton records in opponents batting average (.212), fewest hits allowed (403) and fewest runs allowed (166). 

Dietrich coached pitchers such as Thomas Eshelman, Justin Garza, Tyler Peitzmeier and Michael Lorenzen, all who have since been drafted into Major League Baseball. In 2016, Dylan Prohoroff, Miles Chambers, Chad Hockin and Scott Serigstad each joined those ranks as they were all selected in the 2016 MLB Draft. Eshelman and Garza were each named All-Americans on multiple occasions. Eshelman set the NCAA record with a 0.23 walks allowed per nine innings mark in 2013. Garza pitched the fourth no-hitter in Cal State Fullerton history, holding CSUN without a hit on May 23, 2014.

In 2015, Eshelman posted a 1.58 ERA, the third best single-season mark in Titans history. Freshman Connor Seabold posted a 9.91 strikeouts per nine innings average, which ranks as the ninth best mark in a single season and Peitzmeier recorded 16 saves during the season, which was the third most in a single season behind Lorenzen’s 19 in 2013 under Dietrich and Scott Wright’s 24 in 1984. As a team, the Titans posted a 2.89 collective ERA and tallied 546 strikeouts as opposed to 110 walks. The team was ranked first in the nation in strikeout-to-walk ratio (4.96) and walks allowed per nine innings (1.70). 

Dietrich came to Fullerton after spending five seasons (2008-12) in the UC Irvine program, the last two serving as Head Coach Mike Gillespie’s pitching coach. Over those two seasons the Anteaters posted a combined ERA of 3.10 and a WHIP (walks and hits per innings pitched) of 1.18.

In 2012, Dietrich’s staff set a Big West Conference record for fewest hits allowed (422) in a season, ranking them sixth in the nation in fewest hits allowed per nine innings. He also helped script Irvine’s fifth no-hitter in school history on Apr. 20, 2012, when right-hander Andrew Thurman blanked the Long Beach State 49ers at Blair Field. Dietrich also helped the all-conference first-teamer Thurman to an additional pair of one-hitters against Cal State Fullerton and Cal State Bakersfield.

Under his guidance in 2011, the Anteaters posted their lowest ERA (2.95) in nearly 40 years led by the Big West Pitcher of the Year Matt Summers (11-4, 2.15 ERA, 100 K), who finished conference play with an unblemished 8-0 record and wound up being an All-American and a fourth-round draft pick of the Minnesota Twins. Dietrich was also part of a Summers no-hitter against Long Beach State on May 28, 2011, in Irvine. The Anteaters finished the 2011 season just one win away from their second College World Series appearance with a Super Regional series loss to No. 1 national seed Virginia. Dietrich spent his first three seasons with Irvine as its director of baseball operations.

Before joining the Anteaters in 2008, he was the recruiting coordinator and pitching coach for then-Head Coach Pat Shine’s Cal State Los Angeles Golden Eagles, who won a West Regional championship and finished third at the Div. II College World Series in 2007. Four of his hurlers received all-conference recognition that year.

In the junior college ranks, Dietrich spent four seasons (2003-2006) as the pitching coach at Irvine Valley College where he helped the Lasers to a 2005 Super Regional appearance. He also served in the same capacity at Los Angeles City College, where he assisted the Cubs to a 2002 South Coast Conference championship.

Dietrich’s other coaching experience includes two summer seasons in the prestigious Cape Cod League with the Hyannis Mets in 2004 and 2005, and a season (2003) with the Southern California Fire in the Western Wood Bat Collegiate Summer League. He got his start in 1999 as the varsity pitching coach at Arcadia High School. The Apaches won two Pacific League titles (2000 and 2001) in his three seasons there.

As a player, Dietrich spent three seasons (1991-93) with Rancho Santiago College (now Santa Ana College) before transferring to Pepperdine for a season in 1994. After three straight junior college conference championships he declined an offer from the New York Yankees as a 23rd-round pick to move to Malibu. The right-hander was an All-West Coast Conference honoree under then-Wave Head Coach Andy Lopez and is still in the Pepperdine single-season record book for the second lowest batting average against (.186) and most strikeouts per nine innings (10.77). His 1.66 ERA that year led the WCC and he was eventually a 19th-round pick and signee of the Colorado Rockies.

Dietrich’s professional career lasted five seasons, four in the Rockies’ minor league system and one in the independent Northeast League. He was a combined 7-2 with a 2.39 ERA in four seasons with the Portland Rockies, Asheville Tourists and the Salem Avalanche and 2-0 with a 1.45 ERA with the independent New Jersey Jackals in 1998.

Dietrich owns a master’s degree in physical education from Azusa Pacific University (2001) and a bachelor’s degree from Cal State Fullerton (1999) in criminal justice. He prepped at Mater Dei High School in Santa Ana, Calif.

• Dietrich was coached by former Titan All-American player and Augie Garrido assistant coach Don Sneddon at Rancho Santiago College from 1991-93.

• Dietrich was teammates with future Titan first baseman Jim Betzold and future Titan infielder and coach Jason Gill at Mater Dei High School.

• Dietrich was on the same pitching staff with former Titan and former major league pitcher Matt Wise at Pepperdine in 1994.

• Dietrich played with former Titan national champion D.C. Olsen in his final season of professional baseball with the Northeast League champion New Jersey Jackals in 1998.

• Dietrich was the pitching coach for former Titan All-American and 2008 Big West Conference Pitcher of the Year Jeff Kaplan when he was pitching at Irvine Valley College in 2004 and 2006.

• Dietrich coached along side former Titan All-American pitcher Mike Parisi at Arcadia High School in 2000 and 2001.