In February 2022, a Twitter user datamined Super Mario Strikers to reveal several unused character models. The unused character models include:
• Generic Mario-style humans, and unused Donkey Kong-like characters (most likely suggesting that captains were going to have their own unique sidekicks themed after them).
• An early model for the Medic that resembles Dull Bones from Paper Mario.
• A Security Pianta that only appeared in the pre-release builds of the game.
A Goomba Guard that appears to be related to the cut stage "peach_palace"
Contributed by Yoshispacedragon
This is the only GameCube title with 16:9 widescreen and 480p resolution support.
Contributed by Dazz
An unused promotional poster for Super Mario Strikers was created but ultimately rejected due to its visual depiction of a male scrotum. In the image, two soccer balls dangle from a net bag, with the quote "You're gonna need a pair".
Contributed by Yoshispacedragon