The Boston Red Sox got off to a terrific start, with the best record in baseball through the first month of the season at 18-8.
However, issues in the bullpen could pose a major problem moving forward, as the closer position appears to be up in the air.
Last offseason, the team dealt a package of players to the A's for Andrew Bailey to replace the departed Jonathan Papelbon, who had signed with the Phillies as a free agent.
After posting a 2.07 ERA and 75 saves through his first three seasons in the league, Bailey battled injuries in 2012 and struggled to a 7.04 ERA in just 19 appearances last season.
Though Bailey was healthy to open the season, the team opted to go a different direction in the ninth inning. Two-time All-Star Joel Hanrahan was acquired from the Pirates for four players and immediately became the closer.
Many believed that gave the Red Sox two solid options at the back end of the bullpen, but that has not quite been the case to this point.
Hanrahan posted an 11.57 ERA and converted 3-of-4 save chances through his first six appearances before landing on the disabled list with a thigh strain.
With five scoreless appearances under his belt to start the year, Bailey slid into the closer role with Hanrahan on the shelf, and in eight games he had a 2.25 ERA and converted 5-of-6 save chances.
Can the Red Sox keep winning without a proven closer?
Expected to remain in the ninth-inning role, even with Hanrahan back, Bailey himself is battling injury and was placed on the 15-day DL on Monday with bicep inflammation (h/t ESPN). Bailey has not pitched since April 28, so he is eligible to come off the DL on May 14.
Back in the ninth-inning role, Hanrahan has made three appearances since returning, allowing four hits and two runs in 2.2 innings while blowing one of his two save chances.
If those struggles weren't bad enough, he left Monday night's game with a right forearm strain, and he too could be headed back to the disabled list in the days ahead (h/t ESPN).
So where do the Red Sox go from here in the ninth inning?
There was a time when Daniel Bard was viewed as the closer of the future and one of the most promising young relievers in the game. However, a move into the rotation last season threw his career into a tailspin and he is currently in Double-A trying to get things back on track.
The most likely candidate to take over at this point seems to be Koji Uehara, who signed a one-year, $4.25 million deal as a free agent this offseason.
He's been used primarily as a setup man during his time in the MLB, but he does have experience closing dating back to his time in Japan, as well as the 2010 season, when he went 13-for-15 on save chances with the Orioles.
In 15 appearances this season, Uehara has a 2.63 ERA with 17 strikeouts in 13.2 innings of work. Those 15 games puts him second on the team to Junichi Tazawa, who has made 16 appearances and may also be a candidate for some late-inning work.
A former top prospect as a starter, Tazawa finally found a role in the Boston bullpen last season, making 37 appearances with a 1.43 ERA and 45 strikeouts in 44 innings. He has a 2.51 ERA and 18 strikeouts in 14.1 innings so far this season.
Andrew Miller (14 G, 3.12 ERA) and Clay Mortensen (12 G, 3.78 ERA) have been solid as well this season, but are unlikely to see action in the ninth.
Another option the team could explore is recalling recently demoted Alfredo Aceves and using him as closer, a role he filled last season when he converted 25-of-33 chances filling in for Bailey.
Considering he was demoted after putting up a 8.66 ERA through his first five games (three starts), it seems unlikely the team would trust him in that role at this point.
A dark-horse candidate to see time at closer may be top pitching prospect Allen Webster, who got a spot start already this season and pitched well over six innings.
His future is in the rotation, and the team may not want to throw off his progression through the minors by putting him in the bullpen, especially after seeing what happened to Bard.
However, guys like Adam Wainwright and David Price were contenders out of the bullpen before going on to be front-line starters. While Webster may not quite be on their level, he still has the stuff to get guys out in the ninth.
Going back to the original question though of whether the Red Sox bullpen can survive without a proven closer, the answer right now is we'll have to wait and see.
They have a number of options capable of stepping into the role and succeeding, and enough proven veteran relievers that they could even opt to go with a closer-by-committee for the time being.
The ninth inning is a different animal entirely though, and success in the middle innings does not always translate, so they'll have their hands full in the weeks ahead shuffling the 'pen around to make things work.