Sega Genesis Saving (Not Save State)

First post and really enjoying Retroarch and Libretro. Great job by everyone involved!

One question, I have everything running fine but was curious if there was anything needed to save data to a “cart” (really a rom).

I am playing Triple Play baseball for the Sega Genesis. I have tried both the Picodrive and Genesis Plus GX cores. The game plays fine.

There is a create custom player option within the game. I can make changes but when I click the save button within the game menu it does not save.

I am assuming this is a limitation of playing this game in an emulator but wanted (hoping) it is user error.

Thanks in advance for any responses and keep up the great work!!