NASHVILLE — As poorly as the Red Sox rotation performed in 2015, the collective performance of the bullpen proved even worse. According to some measures, the Red Sox had one of the worst bullpens seen in decades.
In the 21 seasons of the wild-card era, the 2015 Red Sox ranked 610th of 624 teams in Wins Above Replacement (WAR), having been 1.4 wins worse than a replacement-level bullpen. The relievers allowed a franchise-record and major league-high 76 homers while striking out just 20 percent of opposing batters, the fifth-worst strikeout rate in the game.
There was an obvious lack of stuff, made more glaring by the late-season absence of mainstays Koji Uehara after a line drive broke his wrist and Junichi Tazawa, who was shut down for rest. By September, late-inning opportunities fell to pitchers such as Alexi Ogando and Jean Machi, both of whom were released at the end of the year.
Fast-forward two months. The Red Sox, who last month acquired closer Craig Kimbrel from the Padres, advanced what now amounts to a major makeover of their late innings Monday. The Sox swapped starter Wade Miley and reliever Jonathan Aro for 26-year-old righthander Carson Smith and 27-year-old lefty Roenis Elias.
Smith is the centerpiece, a righthander with a sidearm delivery from which he throws a mid-90s two-seam fastball and a wipeout slider, a combination described widely by evaluators as nasty. Apprised that the Sox landed Smith, two scouts at the Winter Meetings had the same, simultaneous reaction: "Whoaaa."
In 79 big league appearances, all but nine coming in 2015, Smith has a 2.07 ERA with 11.7 strikeouts and 2.9 walks per nine innings. With the addition of Smith, two National League evaluators suggested that the Red Sox have the potential for an overpowering bullpen, with wave after wave of swing-and-miss arms — correcting last year's late-inning shortcoming.
"We've got greater arm strength, greater average velocity by this group," said Red Sox manager John Farrell. "To be able to match up, whether it's a righthanded arm-slot difference with Carson Smith and his strikeout ability to [Tazawa] to [Uehara], the strikeout ability is clearly greater right now."
Farrell compared the low arm slot of the 6-foot-6-inch Smith with that of longtime setup man Jeff Nelson. While lefthanded batters have had little success against Smith (.207 average, .294 OBP, .248 slugging mark against in his career), Smith has overwhelmed righties, holding them to a .166/.247/.242 line while punching out 37.5 percent of all righties he's faced.
That trait, in turn, offered considerable appeal to a Red Sox team that has to contend with division rivals that feature tremendous righthanded power, such as the Blue Jays (Josh Donaldson, Jose Bautista, Edwin Encarnacion), Baltimore (Manny Machado, Adam Jones), Tampa Bay (Evan Longoria), and New York (Alex Rodriguez).
"This righthanded arm slot we would hope would give us an advantage," said Farrell.
A year ago, the Red Sox had just one reliever (Uehara) who struck out at least 29 percent of batters while facing at least 100 batters. Now, in Kimbrel, Uehara, and Smith, they have three, a claim that could be made by just two teams (the Orioles and Padres) in 2015.
With those three, plus Tazawa, president of baseball operations Dave Dombrowski noted, the Sox can regulate workloads and theoretically withstand some of the anticipated injuries to the relief corps. Kimbrel can get the ninth, Uehara can claim sole responsibility for the eighth, and the team can employ Smith and Tazawa strategically in a way that proved unavailable last year.
If the team wants to rest Kimbrel, Uehara can close. If Uehara is out, Smith or Tazawa can handle the eighth. There are options.
Elias, meanwhile, is a lefthander who has spent his first two years in the majors primarily as a starter. He has gone 15-20 with a 3.97 ERA, 7.7 strikeouts per nine innings, and 3.5 walks per nine innings.
One scout called him a "versatile lefty with a feel to pitch."
His upside, according to another scout, is roughly the same as Miley's — a back-end starter — though there is disagreement about whether he's better suited for the rotation or relief. One National League evaluator described him as potential knockout left-on-left bullpen option, given that he held southpaws to a .227 average, .299 OBP, and .309 slugging mark while striking out 31.8 percent of southpaws he faced in 2015; righties had a line of .251/.332/.433 with a 16.4 percent strikeout rate against him.
However, an American League evaluator said that Elias struggles out of the bullpen with command and that he needs an inning to settle in before his plus curveball and above-average changeup can play.
Uehara, Smith, and Elias all have proven capable of getting lefties out, and the team was encouraged by the ability of lefties Robbie Ross Jr. and Tommy Layne to do the same in 2015. Dombrowski left open the door to a move by the Sox to add to their lefthanded relievers, but even without such an addition, the Red Sox hope that what proved a late-innings recipe for failure will now more closely resemble an approach that helped yield a championship.
"I think adding that one more arm out there that really gives you that much more comfortable feeling because if somebody does get hurt, you've got that," said Dombrowski. "I wouldn't downplay the success of Kansas City and how good they've been. I think it shows the more guys you can keep trotting out there, the better off you are."
Follow Alex Speier on Twitter at @alexspeier.