The Red Sox began 2014 with one of their best and deepest bullpens (at least on paper) in recent memory. During the offseason, Ben Cherington added reliable veteran Burke Badenhop and 2013 Cardinals closer Edward Mujica to a crop of relievers that already had Koji Uehara, Junichi Tazawa, and Craig Breslow returning after strong campaigns in the season prior.
Given Uehara’s present stature across Red Sox nation, Tazawa’s dependability, and the big role Mujica is expected to play, one could be forgiven for forgetting another Boston reliever who has returned to the bullpen for another season with the Red Sox.
Andrew Miller might not be the most prominent Red Sox player in the eyes of fans, but that doesn’t diminish his importance to the Boston bullpen this season. After Miller tore a ligament in his foot during a game against the Angels last July, missing the rest of the season, it became easy to forget just how well the lanky left-hander had settled into his role as a reliever.
Miller has had a tumultuous career after falling from uber-hyped prospect status as a member of the Tigers and Marlins (he was a main piece in the deal that saw Miguel Cabrera move to Detroit in 2008). Like many tall starters, Miller struggled to repeat his delivery and find a consistent arm slot, a recurring problem that prevented him from fulfilling his lofty potential, and one that still crops up in his role as a reliever.
The Red Sox took a flyer on Miller in 2011 with an eye toward resurrecting the former first round pick’s career. A 5.7 BB/9 in 12 starts during the 2011 campaign, in which Boston was desperate to find another reliable starter, saw that experiment fail, so the Red Sox decided to try Miller in the bullpen where his stuff could play up and his control problems would, hopefully, not be so impactful.
In 2012, that decision proved wise, as Miller made 53 appearances out of the Red Sox bullpen, finishing with a 3.35 ERA, a 3.17 FIP, and an impressive 30.2% strikeout rate. Miller’s fastball velocity, moreover, rose from 93.1 mph in 2011 as a starter to 95.6 mph a year later in the bullpen, as the left-hander was able to max out his efforts over shorter outings. Even more importantly, Miller was now able to focus on throwing just two pitches—his fastball and slider—rather than trying to develop the third pitch necessary to succeed in the big leagues as a starting pitcher.
That season, Miller threw his four-seam fastball 51.0% of the time and his slider on 40.1% of his offerings, according to Brooks Baseball, enabling him to simplify his approach and cut down on his walks just enough to see serious improvements as a reliever.
Miller’s newfound role led to an even better performance in 2013, with the 28-year-old making 37 appearances out of the Red Sox bullpen before suffering that season-ending injury in July. Last season, Miller posted a 2.64 ERA, a 3.05 FIP and an elite 35.6% strikeout rate in 30.2 innings. To put Miller’s performance into perspective, that strikeout rate would have ranked seventh-best among MLB relievers in 2013, ahead of pitchers like Trevor Rosenthal, Ernesto Frieri, and David Robertson.
So far in 2014, Miller is off to a solid start, though the Red Sox have not yet entrusted him in any high-leverage situations. The lefty has allowed two hits and an earned run over 3.1 innings pitched, striking out four and walking three. That the Red Sox would want to bring Miller along slowly makes sense given his return from a long-term injury and his slow start a year ago.
Over his first 15 appearances in 2013, for instance, Miller compiled a 5.40 ERA after allowing six earned runs in his first 10 innings pitched. Many at the time speculated that he could be nearing his final days in a Red Sox uniform if his performance didn’t improve. Miller would allow just three earned runs over his last 21 appearances, though, striking out 30 batters and walking nine, while holding opposing batters to a .585 OPS.
Even more encouraging was Miller’s performance against right-handed hitters, with the 6-foot-7 hurler proving to be much more than a situational lefty. Miller held righties to a .153/.319/.207 line in 2013, using his slider to great effect. He gave up just four hits to righties on the pitch—all singles—and picked up 16 strikeouts versus just one walk with the offering, per Brooks Baseball.
The zone chart below, which shows the swing rate of right-handed hitters on Miller’s slider, demonstrates how Miller was able to frequently get them to chase the pitch down and in, and often outside the strike zone.
Miller hasn’t played a prominent role in Boston’s bullpen yet this season, but considering his track record over the past two years, he still might prove to be an important reliever for the Red Sox. His slow start this year shouldn’t be too much cause for concern, especially when one remembers his rough first six weeks in 2013.
Ultimately, Miller’s abilities to rack up strikeouts and get both lefties and righties out will make him a valuable member of the Red Sox bullpen in 2014.