Rewind to one week ago, when Ryan Kalish was still expected to be a contributing member of the 2013 Boston Red Sox. Well, if necessary, anyway -- Kalish had an option remaining, and was expected to play every day in Triple-A Pawtucket. However, if Boston needed another outfielder, one capable of playing center or right field defensively, Kalish could be called upon without interfering with the 40-man roster as is. While this was the case, the Red Sox were searching for a bat for the bench that could fill in at first and left when needed, and was left-handed in order to complement Jonny Gomes and Mike Napoli.
Bring it back to today, and that's no longer the case. Kalish is set to undergo shoulder surgery that will see him miss all of spring training, if not a significant chunk of 2013 recovering. The only other outfielder on the 40-man roster is Alex Hassan, who is something of a designated hitter listed as an outfielder, one not quite finished his minor-league seasoning, either, so he isn't an option to replace Kalish. Ryan Sweeney, whom the Sox signed shortly after the Kalish news broke, is, but he changes the landscape of the bench by making the club.
Sweeney hit just .260/.303/.373 for the Red Sox in 2012, but part of that was due to the fallout from a concussion suffered in mid-June: his performance after returning included an ugly .091/.167/.212 line in his final 33 plate appearances and 11 games. Sweeney also struggled in his brief stint as the team's leadoff hitter, which, while normally not worth mentioning, might actually qualify here, as Sweeney warned everyone who would listen (and some who did not, such as manager Bobby Valentine) that he just wasn't comfortable in the role. After posting a 398 OPS as the first in the order, Valentine relented and pulled the plug on that experiment. While the overall splits are small, the fact Sweeney has hit .236/.285/.293 as a leadoff hitter in 263 plate appearances, while expressing a dislike and discomfort in the role, is probably a safe indicator that it's not worth fighting that particular battle with his usage.
There are obvious problems in his game -- he can't hit left-handed pitching, he doesn't have much power, he tends to miss time with injury, and he apparently has a mental block about leading off -- but none of those are significant in the role he would fill were he to make the team out of spring training. As the team's fifth outfielder, his primary tasks would involve filling in defensively late in games, as the injury backup to Daniel Nava against right-handed pitchers, and as the second player capable of playing right field on the roster, a situation that could arise should either Jacoby Ellsbury or Shane Victorino end up injured. Given his impressive defensive chops, and .293/.347/.402 line against right-handed pitchers in his career, he's capable of those things.
It's maybe not an optimal choice, but in the crunch of a 25-man roster, having someone who can do multiple things like that is useful -- it's the same kind of reasons that have kept the defensively capable -- but possibly offensively inept -- Pedro Ciriaco on Boston's depth chart for the infield. As said, though, if Sweeney is on the roster, then there's no room for the left-handed bat that can play first base the Red Sox were recently searching for. Sweeney does give Boston a defense-first glove for left who can spell Gomes late in games against left-handed starters, or allows the Sox to pinch-hit for Daniel Nava against lefty relievers with Gomes without giving up defense in the later innings. But as for first base, he's never played the position, and his bat isn't a good fit. He is, however, 6-foot-4, so if the goal is just to get someone tall enough for the position with a glove there in the ninth, and Sweeney shows he can handle the position, maybe there's something to it. Depending on that in January is a little premature, though.
In short: What the Red Sox stated they want is someone who can play first and left, hits righties, and, most importantly, only takes up one roster spot. That player will likely have to come in a trade, though, as such a player doesn't exist on the free agent market or within the organization, and as such, it's going to take two roster spots to achieve the goal. Daniel Nava gives them the bat capable of playing left and hitting right-handers, and Sweeney can do that while also filling in defensively in the rest of the outfield. Both have suggested they would try out at first if the Sox let them, but as of now, there's nothing to that besides a willingness to try.
As of now, between the five outfielders, the four starting infielders and Ciriaco, five starters, seven-man bullpen, designated hitter David Ortiz, and two catchers, the Sox projected roster for Opening Day is already at 25. Mauro Gomez is on the 40-man roster and can be stashed at Pawtucket, but he's right-handed and unproven, and is not an upgrade on Napoli defensively at first, either. If Sweeney makes the team, it might be at the expense of Kalish's 40-man spot, as he could end up on the 60-day disabled list while recovering, meaning the Sox would once again be at capacity. Because of this 40-man crunch placed on top of the at capacity 25-man, it's even more apparent that a trade is the most likely way to blend these multiple needs into a single player. Otherwise, there's just no room anywhere for that luxury, unless the Sox can add a few more non-roster invites to the list. At this late stage, that, at least, seems likely.