Lannan is this kind of pitcher. He relies upon painting the black, and staying ahead of hitters. If he has an off day at all, he can struggle, because his stuff isn't good enough to overcome that (not that he is alone there.) But more than most, he must stay ahead of hitters to be effective or he will simply walk too many guys and/or allow them to sit on a pitch he has to serve up in the zone. And if he is leaving the ball up, he's SOL. If he has his control, stays ahead of hitters, and induced balls that the defense can help him out, he can battle out of jams and look brilliant. But if not, he can look like crap.
If we can replace him in the rotation with guys like Zimmermann that can miss bats and reduce the margin of error, then we should. That's all I'm saying.
Lannan is a smart guy. He is cool and collected, and that rubs off on the entire team. He's an A1 Rizzo-type character guy. And his charity work is excellent, especially for a guy who hasn't made the bucks yet. He even pays attention to the fans.
But he's struggling and this team needs wins. The option I've been calling for is roster management. Lannan's closest comparable on the team is Livan. They don't have stuff, they don't miss bats, but they are at the extremes of success and failure for that style right now. They should regress to middling, it's an inevitability. But Lannan's brains and unflappability, and Livo's sneakiness and smarts make them Major Leaguers, and successful ones. But if Lannan's sucking it up, then you keep Olsen around, who is a more talented pitcher.
I also have a crazy theory about Lannan and hot weather, I'd like to run the data when I have free time in like 20 years.