As far as I'm concerned, the Luis Mendoza experiement is finished. Good pitchers have a K:BB ratio of 3. Bad pitchers are closer to 1.5. Luis Mendoza's career ratio is barely over 1.0 and falling fast. (0.3 ratio so far this year) It's time to take this trainwreck off the tracks.
The Royals will probably drag their heels on a replacement, however, because (1) their organizational philosphy holds that embarrassment is to be savored and winning should only become a priority after winning has been achieved, and (2) there's not an ideal candidate to replace Mendoza right now.
If I were in charge, Aaron Crow would be starting in Mendoza's spot the next time through the rotation, but the Royals are worried about thinning a taxed bullpen, and while there's good reason to believe that Crow can be effective at getting MLB hitters out, it's not clear that he'll continue to have success in a starter's role. His control can be spotty and his repertoire seems to suggest a pitcher that may struggle if he's exposed to a lot of LHH's multiple times through a line-up.
The other option in the short term is Vin Mazzaro. Mazzaro left the worst impression imaginable with Royals management and fans alike by giving up, by my recollection, 14 billion runs while recording negative 2 outs. Then Vinny compounded matters by complaining in the post-game conference that he wasn't given a fair shot. It went something like this:
"Woe is me. I'm only paid $500,000 per year--it's not my job to be ready to play every day. These 14 billion runs were Ned Yost's fault, and I've already taken action to punish the offending party by sleeping with his wife. Also, screw the fans and up yours."
Like I said, embarrassment is a Royal specialty. But the fact is that while Mazzaro is probably not a good pitcher, the numbers suggest that he's probably a lot better than Mendoza. Mazzaro is probably capable of a K:BB ratio higher than 1 and an ERA below 5.00. While these are not heroic feats by any stretch, they are services that Mendoza and Sean O'Sullivan cannot provide.
So do you make a switch?