Could Red Sox acquire both Jon Lester and Cole Hamels?

If all goes according to plan, by the end of the winter meetings the Red Sox will have brought Jon Lester back to Fenway, and maybe even have found another arm to go with him. With the Dodgers, Cubs, and Giants still chasing after the lefty ace, however, it's clear that the team needs a backup plan just in case all of that falls through.

There are plenty of other options out there to replace Lester should he go elsewhere. Some are more impressive than others (say, Max Scherzer) while some are more realistic (say, everyone but Max Scherzer). One name that keeps popping up: Cole Hamels. The Phillies are looking to offload their expensive ace, and while their demands appear to be high, the Red Sox certainly have the talent to acquire him. If nothing else, the Red Sox can likely rely on him to be there at the end of the day if everything else falls through.

And, according to Ken Rosenthal, Hamels probably is "Plan B" for the Red Sox right now. But he doesn't just leave it at that:

Hamels likely Plan B for #RedSox if they fail to sign Lester. Could they get both? Not out of question, sources say.

— Ken Rosenthal (@Ken_Rosenthal) December 8, 2014

There's little doubt that the Red Sox are looking to add more than just one arm to their rotation. But Lester and Hamels?

It's apparently an option on the table, but the caveat regarding Hamels is the same as ever. In a season where the Red Sox seem willing to open their wallets wide and spend big in terms of dollars, it just doesn't make much sense to then surrender a significant price in prospects just for the privilege of adding another significant contract to the payroll.

There are only a few situations where it makes sense to trade with the Phillies, then:

1) If their demands come way down (they have been said to be unreasonably high in the early going)

2) If the Red Sox are truly desperate.

The second scenario could come about if the Red Sox whiff on all the major free agents and can't find any more palatable deal on the market in terms of quality, prospect price, and contract size (Hamels passes the first test with flying colors, but bombs the other two). That would presumably mean not signing Lester since, as good as a rotation starting with him and Hamels would be, there's just no need to bend over backwards and overpay at that point.

Sure, if the Phillies come down and the Red Sox see the opportunity to snipe Hamels on a reasonable deal, they should be willing to add him and Lester both given how much money is coming off payroll in 2015. Otherwise, though, with Hamels already a "break glass in case of emergency" option, it would be pretty nonsensical to add him with Lester already aboard.