BOSTON -- At various times in 2014, the Boston Red Sox had black holes throughout their lineup, but none as consistently nonproductive as third base, where another injury-filled season for Will Middlebrooks created a void the Sox never filled.

The Sox ranked last in the majors in batting average at third base, 29th in on-base, last in slugging. Middlebrooks hit two home runs in 234 plate appearances, none after April 26. Xander Bogaerts, shifted to third after Middlebrooks was hurt, went into a three-month funk at the plate and made 10 errors in just 44 starts at third. Brock Holt performed ably as a fill-in, but was never more than a temporary solution.

The Sox took a brief look at another rookie, Garin Cecchini, in September, but they head into the offseason with perhaps even more uncertainty than they did a year ago, when they bet on a healthy Middlebrooks establishing himself as an everyday player. Outside of starting pitching and another bullpen arm or two, third base would appear to be the position most likely for the Sox to seek an external solution.

Here’s the seventh in our series of position-by-position breakdowns:

Performance this season (major league rankings):

• Batting average: .211, 30th

• On-base percentage: .271, 29th

• Slugging percentage: .308, 30th

• Home runs: 10, 25th

• Extra-base hits: 38, 27th

• Offensive WAR: 0.5, 27th

• Wins Above Replacement: -0.5, 27th

• Errors: 24, 26th

• Total Zone Fielding Runs Above Average: -11, 28th

• Third basemen used: 8

Offensive stats: Will Middlebrooks 60 G, .194/.261/.270/.531 2 HR, 19 RBI; Xander Bogaerts 44, .217/.300/.517 5, 13; Brock Holt 38, .281/.335/.370/.705 1, 14; Jonathan Herrera 9, .125/.276/.125/.401 0, 1; Garin Cecchini 9, .222/.323/.444/.767 1, 4; Ryan Roberts 7, .111/.238./111/.349 0, 0; Kelly Johnson 2, .200/.200/.200/.400 0, 0; Carlos Rivero 2, .500/.500/1.167/1.667

Defensive stats: Middlebrooks 57 GS, 4 E, total zone fielding runs above average 3; Bogaerts 44, 10 E, -3; Holt 37, 6, -7.

Best performance: Holt gets the nod here by default, posting a .705 OPS and holding his own defensively, although the defensive metrics suggest otherwise (-7 total zone fielding runs above average). Until he sustained a concussion in late August, Holt was one of the team’s most reliable performers, regardless of where he played on the diamond. He didn’t play after Sept. 5 because of concussive symptoms, but the club is confident he will make a full recovery.

Biggest disappointment: Middlebrooks turned 26 in September and should be entering the prime of his career. Instead, he has had one physical setback after another and hasn’t performed with any consistency even in those windows when he has been healthy. The Sox wanted him to play winter ball, but he opted to stay in Texas and work out at home; getting healthy, he insisted, took priority over getting more at-bats. It’s hard for a team to move on from the kind of raw power Middlebrooks showed as a rookie, but that will be one of the bigger decisions general manager Ben Cherington will have to make in the coming weeks.

Biggest surprise: It certainly came as a shock to the Sox that Bogaerts’ offensive game would collapse after his shift to third base, although the move only further complicated what was already a daunting challenge for the 21-year-old rookie.

Outlook for 2015: The Sox have signaled a need for another left-handed bat to balance their lineup; this is a position that obviously would lend itself to adding that bat from the outside. Perhaps Cecchini eventually grow will into that role, but he probably needs more time in Pawtucket. The other option is to give Middlebrooks one last chance to fulfill his abundant promise, but the Sox may not have the luxury to wait. The switch-hitting Pablo Sandoval, 28, is a particularly attractive target, but a lower-cost alternative could be the left-handed hitting Luis Valbuena, who hit 16 home runs for the Cubs last season. Looking for a big deal? Should the Athletics elect to move Josh Donaldson, the Sox surely would be interested.

Potential free agent signings: Pablo Sandoval, Chase Headley, Alberto Callaspo

Potential trade targets: Luis Valbuena, Josh Donaldson, Pedro Alvarez, Trevor Plouffe, Aramis Ramirez, Juan Uribe

Prospects in the system: Cecchini

Scout’s take: Middlebrooks’ health has been an issue ever since he fractured his wrist in 2012. Hands are delicate. Jayson Werth, for example, took a long time to recover from multiple injuries to his hands. He was a guy who always had potential when he was with the Toronto Blue Jays and Los Angeles Dodgers, but had issues staying healthy, much like Middlebrooks. Will’s swing has gotten longer since he got hurt, but do you wait to see what happens if he gets beyond his health issues? I wouldn’t count on him for anything. Sure, he still has trade value. A lesser team might be more willing to roll the dice on him in a trade for a middle reliever, say. Boston can’t guarantee him 500 at-bats, but a team that’s not going anywhere could, such as the San Diego Padres. The other option Boston has is to run him out there and let him sink or swim.

A team has to make a list of its question marks going into a season, and if that list is too long, it’s in trouble. Are the Sox putting their neck on the line for Bogaerts, Vazquez, Castillo? Then Middlebrooks is pretty far down that list. And Cecchini is still too raw.