Jeff Locke has been pretty terrible since the All-Star break. Including his last disastrous start against the Diamondbacks, Locke has a 5.58 ERA over 30 2/3 innings in five starts. The guys at Pirates Prospects have been beating the "this is just regression and he'll even himself out" drum pretty hard, but I'm not convinced that adequately explains his struggles. I'd like some more data before I really get into things, but you can see from his Brooks Page that his fastball velocity has both dropped and gotten less consistent this month and it's possible that that's happened because his release point has gone wonky, which might indicate that he needs some straightening out mechanically.
A mechanical problem would be fine, of course, because those can be fixed and don't indicate health problems. Whatever the case, Locke obviously has to pitch better than he did against the Diamondbacks last Saturday. This series in San Francisco is obviously a big one for the Pirates; the Cardinals have four games against the Braves while the Reds beat the Diamondbacks today and will play three against the Brewers over the weekend. A split in San Francisco will probably keep the Pirates at least in a tie first place, and three wins should keep them in solo possession. I think three wins is doable here; the Giants have fallen into last place, they're only 13-19 since the break, and the Red Sox kicked the absolute crap out of them twice earlier this week. Since last Friday, they've given up ten, six, seven, and 14 runs across six games.
Tonight's starter, Matt Cain, hasn't really been a part of that terrible run of pitching. If the Pirates can win this game, with their worst starter matched up with Cain, I think they've got an awfully good shot at taking three of four. First pitch tonight is at 10:15.