I don't have time to do an exhaustive post on the matter and frankly, I don't think it warrants one in the first place, but because the topic did come up internally and I think the answer is interesting enough I'm going to just post a short blurb on it. Depending on the reception below, you may see more of these when the situation arises or you may never see another one again. So let me know if you like hearing about this stuff.
That being said, late inning lefty pitchers; there are not many of them. It is somewhat common knowledge that there are fewer left-handed closers than you'd expect given the overall demographic of Major League pitchers, but the same is also true (albeit to a lesser extent) of set-up men and while there are more late inning lefties, they tend to occupy more LOOGY roles than the you see righties occupying a ROOGY role, no matter how much (Sean Green) they should be.
With that in mind, I present you with a handy number to serve as a reference in the future if you are ever curious.
Percentage of 2008 MLB pitches tossed by a LHP in innings 1-3: 30.48%
Percentage of 2008 MLB pitches tossed by a LHP in innings 8+: 22.41%
It's not a huge difference but it is a statistically significant one and perhaps an interesting open question as to why. Most lefties get every chance to succeed as a starter, thus inflating the percentage of pitches thrown early in the game (generally by starters) by LHP? LHB are less prevelant than RHB and thus LOOGYs are less useful than ROOGYs? I'm not sure and I'm not sure there is any *one* answer.