Miley, Porcello, Masterson head to Boston as Red Sox rebuild rotation

Having missed out on Jon Lester, the Red Sox wasted no time executing a backup plan, adding Wade Miley, Rick Porcello and Justin Masterson to their starting rotation.

The Red Sox may have lost the Jon Lester sweepstakes Tuesday night, but they clearly had a backup plan. Amid an insanely busy final surge at the winter meetings, one that saw the Dodgers radically revamp their roster and roughly a third of the league make a significant trade, the Red Sox acquired Tigers righty Rick Porcello and Diamondbacks lefty Wade Miley, then signed righty Justin Masterson to a one-year contract worth $9.5 million plus incentives. In doing so, they added three established groundballers to their rotation in one fell swoop at the cost of Yoenis Cespedes, righty reliever Alex Wilson and prospect Gabe Speier (for Porcello), and pitchers Rubby De La Rosa and Allen Webster, as well as at least one other minor leaguer (for Miley).

With those three moves, the Red Sox are showing a great deal of confidence in their infield defense, which features arguably the best-fielding second baseman in baseball in Dustin Pedroia and a well-above-average first baseman in Mike Napoli, as well as new addition Pablo Sandoval at third base. The wild card in that group is shortstop Xander Bogaerts, an excellent athlete who was better at shortstop than third base last year according to Ultimate Zone Rating.

• Free agent tracker: Keep up to date with the latest signings

Three Strikes: Aggressive White Sox are offseason's biggest surprise

That's not to say that the Red Sox are taking particularly large gambles on any of those three pitchers. Trading Cespedes, who will hit free agency next year, frees up leftfield for Hanley Ramirez. It also sets up the Sox to get, at worst, draft pick compensation for fellow free-agent-to-be Porcello, something they couldn't get out of Cespedes due to a contract clause preventing teams from making him a qualifying offer. Wilson put up some nice numbers in an 18-game sample last year but is 28 and likely a middle reliever at best, and Speier, who was a 19th-round pick last year, won't turn 20 until April and has never pitched above rookie ball. De La Rosa, who will be 26 in March, and Webster, 25 in February, are still more potential than performance, and De La Rosa has just four team-controlled years remaining compared to three for Miley, who is well established as a major league starter.

Of the two trades, the Porcello swap is the more compelling, as the Red Sox acquired a former first-round draft pick who won't turn 26 until later this month for a package built around 2014 All-Star Cespedes. However, given the number of team-controlled years remaining for the primary players involved, the Miley trade could have the longer-lasting impact.

Miley, who turned 28 last month, was an All-Star and runner-up for the National League Rookie of the Year award in 2012, but has regressed since then due largely to a rising walk rate. Miley walked just 1.7 men per nine innings in 2012, but doubled that rate to 3.4 in 2014. That's not a disastrous figure, and it has been accompanied by an improved groundball rate and a spike in strikeouts (8.2 K/9 in 2014 compared to 6.6 the previous two seasons combined), but it has painted Miley as more of a league-average innings eater (he has averaged 200 innings a year over the last three seasons) than an All-Star. Indeed, his fielding independent pitching mark was 3.98 in each of the last two seasons, a good match for his actual 3.94 ERA over those two campaigns, which worked out to a 97 ERA+.

Jon Lester buys into dream of helping Cubs end World Series drought

That's not an overwhelming return for the two pitching prospects acquired in the August 2012 blockbuster trade with the Dodgers, but it is a fair one given the uncertainty still surrounding those two. De La Rosa, who throws in the mid-90s, posted a 4.48 ERA (87 ERA+) in 18 starts for Boston in 2014. He has the potential to be a similarly-effective mid-rotation arm, but there's no guarantee he'll deliver the league-average seasons that can be safely expected from Miley. Webster, who has all six team-controlled years remaining, has even better stuff but is even further away from turning it into a sustainable career, posting a 5.03 ERA in 11 major league starts with awful peripherals this past season. Either of those two might deliver on their promise in Arizona, but they might also wind up as relievers or worse.

The Red Sox are hoping for more upside from Porcello, the 27th pick in 2007, who is coming off a career-best 3.43 ERA and had a 3.61 FIP over the last two years. Thanks to small improvements in his walk and strikeout rates and in the Tigers' team defense, Porcello has rounded into a quality starter over the last two seasons. After posting a 4.75 ERA (88 ERA+) with a 2.3 strikeout-to-walk ratio and .324 opponent's batting average on balls in play from 2010 to 2012, he has posted a 3.84 ERA (106 ERA+), with a 3.27 K/BB and .307 BABIP the last two years. As that BABIP and his 3.61 FIP over those two seasons indicate, he could do even better with more support from his infielders.

As for Masterson, since being traded from Boston to Cleveland for Victor Martinez in July 2009 and becoming a full-time starter, his performance has ping-ponged all over the place. Check out his ERA+ figures from the last four seasons: 84, 122, 79, 110, 63. That inconsistency suggests that the Red Sox were right to favor Masterson as a reliever in the early part of his career, as he's still a side-arming righty with a rather large platoon split. Over those last four seasons, he has held righties to a .225/.312/.302 line, but lefties have hit .287/.362/.422 against him. Last year, in his worst season to this point, lefties hit .320/.408/.502 against him in 317 plate appearances.

Cubs' addition of Jon Lester the latest in Epstein's rebuilding process

Searching for trends in Masterson's numbers, we find that his ground-ball rate has actually increased in each of the last three years, and that his strikeouts, despite dropping from 2013, have been up the last two years as well. That's encouraging, though his recent control problems — a league-leading 17 hit batsmen in 2013, 36 wild pitches total in the last three years, and 4.8 walks per nine innings in 2014 — are quite the opposite. Given his .347 BABIP this past season, it's safe to assume that Masterson can rebound from that, again with the help of the Red Sox's infield defense. The only question is if he can smooth things out enough to be a innings eater in the back half of the rotation, or if the Red Sox will wind up moving him back to the bullpen.

With these three moves, Boston's 2015 rotation projects as some combination of Porcello, Miley, Joe Kelly, Clay Buchholz, and Masterson, with Brandon Workman and Anthony Ranaudo as alternates in case of injury, collapse, or a move to the bullpen. That's not a particularly impressive rotation. Buchholz and Masterson were awful last year, Miley has been trending in the wrong direction, and Kelly has never made more than 17 starts in a single major league season. Still, one could see it panning out in a manner similar to the Orioles' rotation of consistently mid-level starters if the infield can eat up the absurd number of ground balls generated by everyone but Buchholz. In an increasingly underwhelming AL East, that, along with Sandoval, Ramirez and rookie Rusney Castillo, could put the Red Sox right back in the mix in 2015.

Note: The status of the Miley trade remained uncertain at the time of this writing, with Diamondbacks general manager Dave Stewart telling USA Today's Bob Nightengale Wednesday night that the two teams had not yet agreed on the minor leaguers involved in the deal. However, SB Nation's Chris Cotillo cited sources reporting that the deal would be announced on Saturday. Given that top reporters such as FOX Sports' Ken Rosenthal reported that the two teams have an agreement in place, it seems likely that Stewart, who was just hired in late September, is just hedging until that final piece is in place.