THUNDERCAT SPORTS ACADEMY
THUNDERCAT STAFF
Jonny Rivera - Lead Baseball Instructor
Jonny Rivera is the baseball instructor, and college recruiting coordinator for the high school teams. In addition to working at Thundercat Sports Academy, Rivera is the assistant varsity coach at Slinger High School.
Rivera, originally from Lowell, Indiana, was an assistant coach at UW-Parkside (Wisconsin) for the 2022 spring season. Previously, he worked as an assistant coach for Hanover Central High School (Cedar Lake, IN) until the Covid-19 pandemic shut down the 2020 season. In the summer of 2022, Rivera managed the Waukesha Foxes of the Dairyland Collegiate League.
Rivera obtained an MBA in Sports Management with Concordia University of Chicago. He graduated from Lakeland University in the Summer of 2019 with a Bachelor’s degree in Communication and four years of collegiate baseball experience with the Muskies. Rivera is Driveline pitching design and hitting certified.
Mike Knutson - Baseball Instructor
Currently serving as the assistant coach at Jefferson High School under Hall of Fame Head Coach Greg Fetherston for the past six seasons, Knutson has been instrumental in guiding the Eagles to back-to-back-to-back State Championship appearances, achieving runner-up finishes in 2021 and 2022. In addition, Knutson is a 6th grade teacher at Jefferson Middle School.
Along with coaching duties at the high school level, Knutson works with Jefferson’s Jr. Eagle youth organization coordinating winter workouts and skill development.
Knutson spent two seasons 2017 and 2018 as an assistant coach at Viterbo University (NAIA - La Crosse, WI) working primarily with infielders and hitters. He coached 2017 summer with the Springfield Sliders of the Prospect League and 2020 summer with 15U Edge Baseball (Madison, WI). He has also coached prior summers with Jefferson’s legion program and working as an instructor at Brewers Baseball Academy Camps.
Knutson, a native of Jefferson, WI, played collegiately at UW-La Crosse and Riverland Community College (Austin, MN). He earned his bachelor’s degree in Communication studies from UW-La Crosse in 2016 followed by his master’s degree in Teaching from Cardinal Stritch University in 2020. Coach Knutson's diverse coaching background, ranging from youth to collegiate levels, showcases his passion for developing players and fostering a culture of excellence.
Steven Diderrich Jr - Baseball Instructor
Steven Diderrich Jr serves as the catching coordinator and hitting instructor at Thundercat Sports Academy. He offers hitting, field and catching lessons. Currently, Diderrich is the bullpen catcher/coach for the Lake Country Dockhounds of the American Association, a professional partner league of the MLB.
Seth Feldman - Hitting/Catching Instructor
Originally from Platteville, Wisconsin. Feldman comes to Thundercat Sports Academy as an offseason baseball hitting and catching instructor. Entering his 6th year as a Minor League Manager with the Minnesota Twins Organization, Feldman primarily worked with catchers and infielders. From 2019-2021, he served as Manager of the Dominican Summer League Twins in Boca Chica, DR. In 2022, Feldman was promoted to manage the Florida Complex League Twins in Fort Myers, FL. Prior to the Minnesota Twins, he coached as a Volunteer Assistant at University of Wisconsin-La Crosse where he worked in a variety of functions including coaching catchers, hitters, assisting with recruiting, and coordinating all UW-La Crosse youth camps and lessons.
Feldman is able to speak Spanish and continuing to work towards fluency. He played baseball all four years as a catcher for UW-La Crosse and played on the 2015 & 2016 College World Series teams. Feldman graduated with a bachelor's degree in Sports Management from UW-La Crosse in 2016 and completed a Master's in Coaching and Athletic Administration degree from Concordia University Irvine in 2023.