When a pitcher has a poor start, one of many excuses they offer up is that their mechanics were out of whack. We heard this from Joba Chamberlain earlier in the season — that he was working on his mechanics. Whether it’s true or not we can rarely be sure. Each pitcher has his own set of mechanics, so it’s tough to compare one to another. It looks like Sergio Mitre took this excuse after his poor outing on Friday against the White Sox. Via MLB.com’s Anthony DiComo, we learn that Mitre has worked on his mechanics between starts, “concentrating on keeping his right arm and his body synchronized.” That, he says, will help keep his sinker sinking and away from the upper parts of the zone. We’ll see for sure a bit later tonight.