Frank Kellner became the eighth coach in St. Mary’s baseball history and begins his third year with the team in 2026, entering the season with high expectations for the Rattlers.

After posting a 20-30 record in his first year, Kellner and the Rattlers added nine wins to that total in 2025 and advanced to the first week of the Lone Star Conference Tournament, pushing rival St. Edward’s to the final out of the third and decisive game. The Rattlers were picked ninth in the preseason poll, finishing in sixth place, winning six season series and splitting another five. StMU took three of four games at #25 West Texas A&M one week after splitting the four-game set with #15 St. Edward’s during the regular season.

Thirteen different Rattlers hit a home run during the 2025 campaign, setting a new school record for the most players with a round-tripper, and the club hit 60 for the year, the fifth-most in single-season history. At the conclusion of the year, senior third-team all-conference selection Easton Parrish was drafted in the inaugural BBCL draft by the Savannah Bananas.

In 2024, the Rattlers tallied three wins over nationally-ranked teams, including two over fourth-ranked West Texas A&M. The Rattlers won one conference series and split five others during the 2024 campaign.

Senior catcher/designated hitter Devin Goins was named to the Lone Star All-Conference Second Team, while senior utility player Easton Parrish was tabbed on the All-Academic team.

Kellner joined the Rattlers after spending 20 seasons as an assistant coach at Temple College, where he was a part of 657 wins, two NTJCAC Conference Championships, and six second-place finishes. Over 200 players went on to careers at the university level, and 36 players were drafted by the MLB.

Kellner also was a four-time NTJCAA All-Star game coach, being selected for the honor in 2006, 2007, 2010 and 2011. The Leopards made three JUCO World Series appearances (2006, 2010, 2018) and 13 NJCAA Regional appearances in his 20 seasons.

In addition to his 20 years at Temple, he has coached at Louisiana Tech and played professional baseball with the Houston Astros and Milwaukee Brewers organizations, reaching AAA in five of his eight years in Minor League Baseball and playing over 900 professional games as a shortstop. In 1993, Kellner was a Texas League AA All-Star. 

Kellner also founded and directed the Temple Baseball Academy in 2013, running the camps for seven years.

While with the Jackson Generals, Houston’s AA team at the time, Kellner had the opportunity to play on campus at the old VJ Keefe Field from 1991-93. 

He comes from a long line of talented athletes, as his father was a pitcher in the major leagues for two seasons and spent eight years in the minor leagues, while his uncle pitched in the majors for eight seasons. His brother, Joe, was also on the 1980 University of Arizona National Championship team.

He graduated from Louisiana Tech in 1990 with a Bachelor of Science in administration and business. He and his wife, Jennifer, have two daughters, Elise and Clare.