...right next to your Summoner Spells, where the team can see it.
Necessary? No, not really. But it's too late to tell an ally they have the wrong Masteries when you see it in the loading screen.
Just an idea.
your ally should pay more attention in champ selection to runes. masteries and summoners spells and stop tabing out during it... that is why the afk checker is there forcing you to ban if you dont you are kicked from the queue and to lock in a champ and if you dont you are kicked from the queue
people make mistakes its happens but not to the tragic % that is ruining games for the community as a whole... and with all the other issues with the game RIOT has plenty on their plate to get to 1st and get right before they try to change this
