Answer
Trevor Wittman has been the longest-tenured coach of Justin Gaethje throughout his professional career. Wittman has been Gaethje's coach since Gaethje's early days in the UFC, and has helped Gaethje to become one of the most successful lightweight fighters in the world. Wittman is a highly respected coach in the MMA world, and is known for his ability to develop and train fighters to their full potential.