Yellow cards are a joke in this league, honestly Song deserved a dozen red's and another probably 50+ yellows in his time at Arsenal, as did Mascherano(less bad) not really for terrible fouls, just persitant fouling. Certain players just get away with stuff, DM's in general get away with less yellows than most(well DM's at top 4 clubs), or big name players. I still think back to the Barca game, Song a yellow card inside what 2 minutes and another 10 or so fouls in that game of which at least 4 deserved a yellow card, and everyone after the 4-5th foul deserved a second yellow for persistant fouling.
Suarez probably already deserves 10 yellows for diving, he'll have to really up his game and dive more often to get 10 yellows in a single season for it, ref's are crap.