I'll start from scratch. Home Movies was a cartoon by Loren Bouchard and Brendon Small. Loren went on to create Bob's Burgers, and Brendon made Metalocalypse. Brendon's also been on Bob's Burgers a couple of times as "Animal Control Guy". H. Jon Benjamin was one of the lead actors on Home Movies, and one of the characters he played was a lousy soccer coach called Coach McGuirk. Another main character was Melissa, played by Melissa Galsky, who's a production coordinator on Bob's Burgers and has done a ton of "little girl" voices on Bob's Burgers. In this episode, she played "Mara," one of the soccer players who had a look kind of like her Home Movies character.
The main character on Home Movies was Brendon. When the referee in the Bob's Burgers episode came out of the Portapotty, the wordless character with the weird pointy orange hair looked just like him.
Also, the squeaky voice that H. Jon Benjamin used for a couple of the soccer kids sounds a lot like the squeaky voice he used on Home Movies, but that might not be a conscious reference so much as him not having a huge vocal range.