The Sumo of All Fears - S1.E10

After not being able to lift a prob while on set, Mikey decides to go to a gym and get stronger. A sumo named Yokuzuna becomes Mikey's newest rival and a mysterious trainer helps Mikey in defeating him.

On a tennis court, Gonard is working on his game until he is embarrassingly defeated by the ball machine. When the rest of the cast asks what happened, he describes an assailant that sounds exactly like the ball machine.