One of the biggest strengths of the 2011 Philadelphia Phillies was the bullpen's ability to set down left-handed hitters with aplomb, thanks mostly to Antonio Bastardo, who held opposing lefties to a .145 batting average in 69 at-bats.
However, that strength was simultaneously a weakness, due to Bastardo being the only left-handed pitcher out of the bullpen for late-inning, high-leverage situations. While the likes of Mike Zagurski, Juan Perez, and J.C. Romero had stints in the 'pen, the heavy lifting was done by Antonio, and by September, the ill effects of being overworked reared its head, as the 25-year-old struggled in the waning weeks of the season.
The lack of a second, reliable lefty also gave opposing managers a leg up on Charlie Manuel, as they could choose their pinch hitters more effectively, knowing that Bastardo was the only lefty awaiting them in the late innings. It was a glaring flaw in the Phillies' armor, and one that they are intimately familiar with, given that opposing teams stack their bullpens with left-handed relievers in order to neutralize the heart of the order come October.
For this reason, one of Ruben Amaro's greatest tasks this off-season should be to find a suitable left-handed relief pitcher, not only to make the 'pen even more dangerous, but mostly to lessen the burden on Bastardo.
Thankfully, there is no shortage of left-handed pitchers on the open market, which gives the Phillies more than enough options. The cream of the crop is Darren Oliver, who has quietly been one of the better relief pitches in the game over the last four seasons. He'll be relatively inexpensive, as far as relievers go, but he'll be 41-years-old, and more importantly, his Type A free agent status will cost the Phillies a first round draft pick should they choose to sign him.
Instead, the Phillies should look at one of the lower tier options to fill out their bullpen, like Mike Gonzalez or George Sherrill. Both are veteran pitchers whose prime is behind them, but have still displayed the capacity to be effective, especially against left-handed pitchers.
If the hunt for a veteran lefty proves to be fruitless, they can always look within the organization and hope that a young player, like 24-year-old Jake Diekman, who had a 3.05 ERA with 83 strikeouts in 65 innings pitched at Double A ball in 2011. While players like that are not without flaws and longshots to make the roster and would need to greatly impress in spring training to even warrant consideration, it couldn't hurt the Phillies.
It's important to note that the Phillies don't need to splurge or spend a lot of money on any left-handed pitcher that happens to come their way, because the notion of having a second lefty out there is perhaps as valuable as having one who can perform. And while it would be nice to have another Antonio Bastardo getting the call in the late innings, the Phillies should be more focused on getting someone who can take some of the workload off the young lefty.