No. 1: Rick Porcello
No offense to Porcello, but he's not exactly the return on Yoenis Cespedes I was hoping for. The 26-year-old right-hander is coming off his best year to date (3.43 ERA, 1.23 WHIP), but the 4.30 career ERA over six MLB seasons doesn't exactly scream "ace." He'll be a free agent after this season, so Boston doesn't have the luxury of having him locked up for the future. One concern would be Porcello transitioning from the cavernous Tigers home park to compact Fenway, but his road numbers were actually superior to his home stats each of the past four seasons. He has good control as he walked just 45 batters in 204.5 innings pitched, but since he relies heavily on his sinker he also doesn't miss many bats (5.67 strikeouts per 9 innings). It feels like Boston could have held out for more given the power upside Cespedes provides, but barring another move Porcello looks like the Opening Day starter in Philadelphia.
No. 2: Clay Buchholz
The Red Sox are hoping Buchholz can put his miserable 2014 season behind him and revert to the All-Star caliber starter he was in years past. Our new friends FIP and xFIP show that the now 30-year-old starter's campaign wasn't as bad as the 5.34 ERA would lead you to believe. His 2014 FIP was 4.01, his xFIP was 4.04 and he tossed a pair of complete game shutout gems (albeit vs. Tampa Bay and Houston) that leave some hope he still has No. 2 upside left in that arm. He needs better fastball command and increased velocity, as those betrayed him last season and allowed opposing hitters to sit on his devastating changeup. His health is always a question mark, but when 100% in the first half of 2013 Buchholz pitched like a Cy Young candidate (9-0, 1.71 ERA).
No. 3: Wade Miley
The 2012 All-Star has seen his ERA increase each of the past two seasons. Fangraphs' advanced stats, fielding independent pitching (FIP) and expected fielding independent pitching (xFIP), paint a better picture of the left-hander's shaky 2014 season. While his ERA ballooned to 4.34, his FIP was 3.98 while his xFIP finished at an even more respectable 3.50. The soft-thrower induces a lot of ground balls (51.1% last season) and is a bargain at $500K for the coming season. He's fresh off a year where he posted a career-best strikeout rate of 8.18, but an increase in walks accompanied the uptick in K's (78 free passes in 201.1 innings pitched). There's always concern with an NL pitcher making the move to the AL, but Miley's a reliable, middle-of-the-rotation starter who was worth the Rubby De La Rosa/Allen Webster package.
No. 4: Justin Masterson
The Red Sox did reunite with a homegrown starting pitcher this offseason, but it wasn't Jon Lester. Masterson returns to Boston hoping former pitching coach and current skipper John Farrell can fix his unorthodox mechanics, a riddle the Cardinals couldn't solve despite their best efforts. Masterson posted a 3.73 ERA in 160.1 innings under Farrell's watch from 2008-2009, and the Red Sox manager was successful in solving what ailed Lester following his porous 2012 season. Masterson does have a pair of really successful years in Cleveland to his credit before the train went off the tracks. He posted a 3.21 ERA in 2011 and earned an All-Star nod in 2013, ultimately finishing with a 3.45 ERA and career-best 195 strikeouts. But with his three-quarters delivery gone awry last season, the numbers were truly hideous: 5.88 ERA, 1.63 WHIP, 71 walks and 15 hit batters in 128.2 innings of work. The sinker-baller's a reclamation project with No. 3 starter upside, but it's hard to count on the soon-to-be 30-year-old.
No. 5: Joe Kelly
After being acquired from St. Louis in the John Lackey trade in late July, Kelly did what a back-of-the-rotation starter is supposed to do: keep his team in the game. In his 10 starts with Boston, the 26-year-old had six quality starts and only one game where he allowed more than four runs. He posted a 3.08 ERA across his first two major league seasons with the Cardinals, but the advanced numbers cite some luckiness there as his FIP over that time period was 4.00. His upside is limited and his 1.36 career WHIP shows his propensity to get himself into jams, but he's a serviceable No. 4 to No. 5 starter, particularly with a team that has an upper-echelon offense.
Top Prospect: Henry Owens
The 2014 Eastern League All-Star and MLB Futures Game participant dominated Double-A batters in 2014. He went 14-4 with a 2.60 earned run average, actually raising his career ERA with Portland to 2.44 in 26 starts. His 38 innings in Triple-A weren't as impressive (4.03 ERA), but he maintained his strong strikeout rate (10.42 K's per 9 innings). He's a fastball-curveball-changeup lefty who could get a crack at the big leagues around the 2015 midseason mark once the Red Sox ensure they won't lose a year of team control on him. However, it's more likely the 22-year-old marinates at Triple-A for an entire season and becomes a Red Sox rotation staple in 2016.
