Scott Bieber

General Manager

I am now a retired CPA after 43 years in public accounting with Nichols, Rise & Company. This business background has given me useful skills and experience for my role here as general manager as well as overseeing the construction of the original First Serve facility and the 2023 addition. I was one of the founding members of the Siouxland Tennis Association, which has its roots in a birthday party for a long-time doubles group member we decided that Siouxland needed to grow tennis here and that no one else was going to step forward to do that.

There have been so many tournaments and matches, but winning the South Dakota Adult Open A mixed doubles title in the 1990s with my wife, Lynelle, is one at the top of the list. Another top memory is being in the 2nd row at the Bull Ring stadium (now demolished and replaced with a larger on) the French Open in 2017.

I am a voracious reader, mostly fiction suspense thrillers. My wife and I have done various bicycling tours in the US and Europe and I still enjoy riding my bike. We love to travel, especially to historical sites and museums. Of course, I love watching professional tennis and other sports on TV. As a Nebraska resident, it goes almost without saying that I’m a diehard Husker fan.

Fun Fact: I got my first tennis racquet for my birthday at age 11. It was a wooden Bancroft model, complete with press to keep it from warping.

Isabelle Wostoupal

Tennis Director | Pro Shop Manager | RSPA Professional

Hi! I’m Isabelle! My tennis journey began at the age of 14, and it was love at first rally. That spark blossomed into a career that feels more like a passion than a job. After a rewarding experience playing collegiate tennis for North Central College I returned to my roots; earning my degree in Graphic Design and Marketing from the University of Nebraska-Omaha.

While my studies were focused on design, my heart remained on the court. During my college years, I dedicated my time to volunteer coaching at Millard South High School and instructing at Champions Run Country Club and the Maple Athletic Complex. These experiences solidified my desire to embark on a professional coaching career. Before moving to Sioux City, I had the honor of serving as the Head Girls and Boys Coach at Millard North High School for two years.

I have been a proud team member of First Serve since 2022. In 2023, I became First Serve’s Tennis Director and earned my Racquet Sports Professional Association (RSPA) Tennis Professional Certification. In fall of 2025, I took on the role of Head Girls Tennis Coach for Bishop Heelan. My passion lies in merging my two worlds. My creative background enables me to help players visualize their potential and reach new heights. I find inspiration in the unique journey I share with each of my students. I am grateful to contribute to the growth of our vibrant tennis community.

When I’m not on court, you can usually find me expressing my creativity through painting, ceramics, and crocheting. I also share my time with three very important “assistant coaches,” my adorable cats, Blue, Bonx, and Brutus.

Fun Fact: I have played tennis on three different continents.

Tommy Lentz

Assistant Tennis Director | Head Strength and Conditioning Coach | League Coordinator

I have over 20 years on the court and nearly a decade of coaching experience. I bring both playing experience and professional expertise to First Serve as a Racquet Sports Professional Association (RSPA) Certified Tennis Instructor and NSCA Certified Strength and Conditioning Specialist. I also graduated from Creighton University with a B.S. in Exercise Science, and a minor in Behavioral and Cognitive Neuropsychology. This allows me to develop well-rounded players who excel in technical skills, athletic performance, injury prevention, and overall conditioning. I love creating a positive and friendly environment where players of all ages can fall in love with the game, and building the physical foundation to compete at their highest level.

My favorite tennis memories are playing on court with my family and friends. When I am not on court or in the weight room, you will find me behind the drum kit or a piano, producing music, or playing card games. I also enjoy college football.

Fun Fact: I can rip a mean drum solo.

Taylor Jenness

Head Tennis Professional

I’m coach Taylor, one of the biggest tennis fanatics you’ll ever meet! Although, I did find my passion (tennis) late in life, I plan on making up for it with extreme dedication to self-improvement and the game of tennis in general. Growing up I played baseball, basketball, and golf. I feel as though tennis was not as popular around this area, which is a shame, and I hope to help change that! My favorite tennis memories are playing with a group of friends under the lights of Leif Erikson Park courts. Some of my hobbies outside of tennis are baseball, hiking, computers, and watching sumo.

Fun Fact: I have a grey tuxedo cat named Lagatha.

Sophia Guntren

Tennis Instructor

My name is Sophia Guntren, and I am currently a senior at Morningside University and a member of the tennis team. I have been playing tennis for about five years and coaching for approximately four years. I originally picked up tennis as a hobby, but I quickly fell in love with the sport, and it has since become a major part of my life. I grew up in the Sioux City area in Sergeant Bluff, Iowa, with my parents, two younger sisters, and our dogs. I hope the children at First Serve find the same joy and passion for tennis that has had such a positive impact on my life.

My favorite tennis memory is traveling with my college tennis team and winning the GPAC tournament. Some of my hobbies and interests are shopping, doing puzzles, going on walks, playing with my dogs, and spending time with friends and family.

Fun Fact: I have two younger sisters who also play tennis.