Brian McCann signed a five-year, $85 deal this weekend, with an option to extend the deal to 2019. He’ll spend the next five or six years playing for the Yankees, enjoying the short porch in right field and providing New York with above average production from behind the plate.

I’ve made it pretty clear how I feel about McCann on this site several times now, so I won’t spend much time repeating myself. I think the deal he signed with the Yankees is fair. I think he’s undervalued by the “all contracts are bad contracts” crowd. I don’t think it’s a given that he’ll move from behind the plate in three years.

But, none of that matters now. Regardless of where you stood on the great (albeit short- lived) McCann debate of the 2013 offseason, Mr. Fun Police won’t be behind the plate for the Red Sox anytime soon.

That’s ok. There are plenty of other options for the Red Sox to pursue, and they have ample opportunity to improve their team. McCann is really the only free agent option off the board who made any sense for the Red Sox to this point, and many viable options remain.

But make no mistake about it: the Red Sox do need to make some sort of move this offseason to remain favorites (or co-favorites) for the 2014 AL East crown.

I’ve addressed this a bit over the past few weeks, but I believe the “Nick Punto deal” has led many Red Sox fans to somewhat overvalue the concepts of payroll flexibility and short-term contracts. Yes, we could’ve been burned by the Carl Crawford deal and Josh Beckett’s extension. Yes, getting rid of those deals was great for the club.

That doesn’t mean that the Red Sox should avoid long-term commitments like the plague, and it certainly doesn’t mean that every contract the Red Sox offer should be judged on a pure dollars-per-wins basis. I’m not going to dive into the idea of opportunity cost in baseball or marginal wins or why wins are worth more to some teams than they are to others. We can all accept that the Red Sox are a good team with many key players in place but with many holes, and that while they certainly can compete in 2014, they’ll be in worse shape than they were last season if they simply stand pat.

Let’s look at this simplistically: Jacoby Ellsbury (5.8), Mike Napoli (3.9), Jarrod Saltalamacchia (3.6) and Stephen Drew (3.4) were worth a total of 16.9 fWAR last season. All four players are still on the market, but as of today, it looks somewhat unlikely that any will be back.

Ryan Lavarnway is a great player to have in your organization, but a starting catcher he is not. Photo by Kelly O'Connor, sittingstill.net.

Ryan Lavarnway is a great player to have in your organization, but a starting catcher he is not. Photo by Kelly O’Connor, sittingstill.net.

Does that mean that the Red Sox are poised to win 17 fewer games in 2014 than they did in 2013? Of course not. Jackie Bradley Jr. and Xander Bogaerts are likely to account for at least 5 fWAR themselves, and it’s reasonable to hope for more. Mike Carp squeezed 1.2 fWAR out of just 243 PA last season: who’s to say he can’t do more with a full workload? It’s unlikely that Will Middlebrooks produces just 0.3 fWAR again, and there’s even some hope for the likes of Ryan Lavarnway, Dan Butler, Christian Vazquez, Alex Hassan and any other minor leaguer you think might be able to provide value in the MLB lineup.

But you’d have a hard time convincing me that group will come terribly close to replacing the 17 fWAR the Red Sox are about to lose. And while it’s easy to cite players who could surprise us in a positive way, that’s a two-way street.

Do you really want to bank on Ortiz, Victorino and Ross staying healthy all year? Think Koji is going to be worth as much as a No. 2 starter again? Want to bank on all of the youngsters living up to their projections?

I don’t, and the Red Sox don’t have to. As the incomparable Alex Speier broke down in this column, Boston has around $32.25 million to spend this season before they reach the $189 million luxury tax threshold. I understand that the Red Sox aren’t going to want to empty their pockets until all of that money is spent, as having financial flexibility midseason can be hugely important, as it was with Jake Peavy. I also understand that the money should be spent purposefully.

But the Red Sox are not a team without holes. As of the start of free agency, they have a gaping one behind the plate, one at first base and a thin left side of the infield. Their lineup is noticeably thinner than it was last year, to the point where the bottom-third could be fairly laughable.

Here’s a look at what Boston’s lineup might look like if no significant free agents are signed or retained and no major trades are completed:

RF: Shane Victorino
1B: Daniel Nava
2B: Dustin Pedroia
DH: David Ortiz
LF: Jonny Gomes/Mike Carp
SS: Xander Bogaerts
3B: Will Middlebrooks
CF: Jackie Bradley Jr.
C: David Ross/Ryan Lavarnway

That’s a lineup that needs a Napoli or a Carlos Beltran or a Curtis Granderson. I know we live in fear of the long-term contract, but it could use an Ellsbury or a McCann or a Shin-Soo Choo, too. With a deep rotation and a deeper bullpen, the Red Sox can primarily afford to focus on the offense this off-season, and it’s clearly in need of some upgrading, as is the bench.

Keep this in mind the next time you read that the Red Sox will be fine with Bradley in center or fine with Nava or Hassan at first or fine with Ross and Butler behind the plate. They might be fine with one of those scenarios, but can they really survive all three?

There’s no reason we have to find out.