The Orioles didn't pitch well out of the rotation or in relief during the opening month, jumping out to the worst collective ERA (5.89) of any American League team. Baltimore's ERA for May (5.11) ranks 10th in the league, and the bullpen has provided most of the fuel for the turnaround.
Baltimore's relief staff carried a 6.14 ERA through 22 games in April and has improved to 3.96 through 16 games in May. Part of that discrepancy comes from the absence of Radhames Liz, who allowed 10 earned runs in two appearances. Baltimore's relief ERA for April drops to 5.10 if you exclude Liz.
From there, the case gets a little bit murkier. The bullpen cast has remained relatively stable in May, save for some minor changes around the edges. For instance, relievers Liz and Matt Albers are now pitching in Triple-A Norfolk and Dennis Sarfate has gone on the 15-day disabled list.
Otherwise, the roles remain largely the same. Baltimore underwent a brief crisis in confidence regarding late-game relief, but has pressed on with closer George Sherrill during the last two weeks. And Sherrill has responded, pitching to a 1.50 ERA in May and converting his past three save opportunities.
Danys Baez, who was solid in April, has been fairly unhittable in May. The veteran has a 0.96 ERA in six appearances, allowing five hits in 9 1/3 innings. Long reliever Brian Bass has also improved markedly, notching a 2.25 ERA in eight innings after leaving April with a 6.35 mark.
The Orioles also have two relievers who were expected to thrive and have struggled thus far. Setup man Jim Johnson got off to a decent start in April, but has a 5.79 ERA in May. And Chris Ray, long thought of as next in line for the closer's role, logged 6.14 ERA in April and a 5.06 ERA in May.
Ray, like Baez, missed all of last season while recovering from ligament replacement surgery on their respective elbows. And despite their divergent results for the year thus far, both Ray and Baez will be watched carefully for signs of fatigue as the season progresses.
Overall, Baltimore's bullpen has worked through some perplexing trends. The Orioles' relief staff has thrown 133 innings, which ranks second among AL teams. It has also struck out more batters (112) than any AL bullpen and allowed more hits (154) and a higher average (.291) than all but one.
Even with the rapid improvement, Baltimore is 7-9 in May and has gone 3-4 in games decided by two runs or less. Still, a recent organizational move provides room for optimism: The Orioles will now slot Mark Hendrickson among the relievers, better fitting the team's preseason blueprint.
Baltimore's starting staff -- which has logged a 5.76 ERA, good for 13th in the AL -- was expected to be a tad unsettled, and the 'pen was supposed to compensate for that. Now, with Hendrickson and Bass splitting the long relief duties, the bullpen's roles appear to be properly defined.
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.