Athletic Trainer Bios
Chicago Cubs
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Director of Athletic Training

Mark O'Neal

Mark O’Neal joined the Chicago Cubs in 2004 as Head Athletic Trainer, and he was promoted to his present role as Director of Medical Administration in October 2012. Prior to his career with the Cubs, Mark spent the During his career in the athletic training room, among Mark’s proudest moments was working the 2009 MLB All-Star game in St. Louis and being a part of the 2016 World Series Champion Chicago Cubs organization.
Over the span of his career in baseball, Mark has received numerous honors from both his peers and athletic training organizations. In 2008, Mark, alongside Cubs’ Assistant Athletic Trainer Ed Halbur, was part of the 2008 Major League Athletic Training Staff of the Year. In 2007, O’Neal was elected by fellow MLB athletic trainers as Secretary of the Professional Baseball Athletic Trainer’s Society. After serving his peers as Secretary, O’Neal was awarded one of the highest honors among PBATS members when he was unanimously elected President in 2013. Now serving in his third term as PBATS President, O’Neal has truly left his mark on the society in a huge way. Mark led the reinvigoration of the PBATS tobacco education program (ProTep), and worked to expand the PBATS reach into areas outside of the game of baseball as he helped develop the Ability Transcends Challenges program (ATC). This program is designed to educate the American public about disability inclusion in sports and in the workplace. Mark’s work on the ATC program has led to millions of Americans being made aware of the issue of disability inclusion. He has also forged partnerships with the National Down Syndrome Society and the Ruderman Family Foundation; two of the largest disability advocacy groups in the world. Mark also spearheaded PBATS’ efforts to build one of the largest scholarship annuities in NATA history from a single organization. A graduate of the University of Arkansas, Mark worked for the Razorbacks’ football and basketball teams during his time in school. Outside of baseball, Mark enjoys having his private pilot’s license and flying with his sons. Mark and his wife, Stefanie, reside in Chicago with their three children – Conner, Cade and Kyle.

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Head Athletic Trainer

PJ Mainville

PJ begins his seventh season as the head athletic trainer for the Chicago Cubs. Prior to joining the Cubs, he completed the previous two seasons (2011-2012) as the Assistant Athletic Trainer for the Arizona Diamondbacks. Mainville spent 13 years in the Minor Leagues with the Baltimore Orioles and Arizona Diamondbacks organizations. He served as the Minor League Medical & Rehabilitation Coordinator from 2007 to 2010 for the Diamondbacks. Prior to the 2007 season while serving in the Baltimore Orioles minor league system, he was the Head Athletic Trainer for the AAA Ottawa Lynx (2004-2006), AA Bowie Baysox (2001-2003), High-A Frederick Keys (2000), Low-A Delmarva Shorebirds (1999), and Rookie Bluefield Orioles (1998). He began his interest in professional baseball as an undergraduate intern with the Baltimore Orioles in 1996 and 1997 while attending East Carolina University. A certified member of the NATA, Mainville later earned his Masters of Science degree in Performance Enhancement from California University of Pennsylvania in 2005. A native of Warrenton, VA, Mainville now resides in Chicago, IL with his wife, Michele, and children Kylie, Caden, and Carter.

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Asst. Athletic Trainer

Nick Frangella

Nick begins his second season as assistant athletic trainer for the Chicago Cubs. He joins the major league staff after serving as an athletic trainer in the Cubs’ minor league system for 13 years. Most recently, Nick served as head minor league athletic training and performance coordinator (2013-2017). Prior to this, he was head athletic trainer for the Iowa Cubs (2012-2013), Tennessee Smokies (2008-2011), Peoria Chiefs (2006-2007), and Boise Hawks (2005). Frangella was an Athletic Trainer for the Mesa Solar Sox of the Arizona Fall League (2011) and has also earned Southern League Athletic Trainer of the Year honors in 2009 while with the Tennessee Smokies. Nick served as PBATs Athletic Training intern for the Chicago Cubs during the 2004 season at the major league level. He earned a Bachelor of Science degree from Illinois State University in 2004 and a Masters Degree from California University of Pennsylvania in 2007. Nick was raised in Oak Forest, IL and resides in Chicago.

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Asst. Athletic Trainer

Matt Johnson

Matt is in his eighth season as assistant athletic trainer for the Chicago Cubs. Matt joined the Cubs’ major league staff after serving as an athletic trainer in the Cubs’ minor league system for 10 years. Matt has made stops at Mesa (Rookie), Boise (Short-Season), Peoria (A), West Tenn. (AA), Tennessee (AA), and Iowa (AAA). Matt was the athletic trainer for the Iowa Cubs from 2008-2011. In 2008, he also served as the athletic trainer for the Aguilas de Cibaenas in the Dominican Winter League. Matt graduated from Ohio University with a Bachelor of Science degree in athletic training. He earned a Master’s degree from Boston University in applied anatomy and physiology. Matt is a Certified Athletic Trainer (NATA), Certified Strength and Conditioning Specialist (NSCA), a Corrective Exercise Specialist and Performance Enhancement Specialist (NASM), has his CFAS (Gray Institute), is ASTYM Certified and is a Certified ART provider. Matt was born and raised in La Grange Park, IL. He and his wife Rachel, reside in Stow, Ohio with their kids Sam, Brian and Maggie.