When you launch the game, it opens a browser tab and you choose your game mode through its “web portal” thing. whatever you select, itll hook into the game and launch it from there.
I have not done this but it was mentioned on reddit:
“Launch bf3 from battlelog in your native Linux browser by changing your user agent to a Windows one. No need to install Firefox in the Wineprefix. You just need to make sure Origin Web Helper is enabled in Origin’s settings.”