On the morning of last week’s trade deadline, the last-place Boston Red Sox dealt Jon Lester, their best starting pitcher and second-longest-tenured player, to the Oakland Athletics, touching off a day of divesting that completed the defending champions’ transition from preseason favorites into a team that’s playing for 2015. In the wake of the exodus, which robbed the roster of several familiar faces and six Sox World Series rings (plus Jake Peavy and Felix Doubront, who were traded before deadline day), Fenway felt funereal.

Even after the Red Sox sold, though, and despite their double-digit deficit in the wild-card race, the rebirth of Boston’s roster seemed as inevitable as the clichéd phoenix analogy with which I almost started this sentence. What the Sox did wasn’t so much a fire sale as a strategic controlled burn, the culmination of a 10-day planning/sleep-deprivation session designed to engineer the kind of quickie rebuild that turned the Red Sox around in late 2012 and led to a title in 2013.

In the days after the deadline, a series of procedural moves brought the 2015 team into clearer focus: The Red Sox welcomed trade spoils Cespedes, Allen Craig, and Joe Kelly, recalled Mookie Betts and Anthony Ranaudo from Triple-A, and activated Will Middlebrooks from the 15-day DL. (The Sox reassigned Ranaudo to Triple-A temporarily after he beat the Yankees on Friday.) Since then, they’ve added reliever Heath Hembree, a product of the Peavy trade, to the 25-man roster, and bumped catching prospect Blake Swihart up from Portland to Pawtucket. Rookie catcher Christian Vazquez and 25-or-under arms Allen Webster, Brandon Workman, and Rubby De La Rosa were already on the big league roster, along with Xander Bogaerts and Jackie Bradley Jr., and a number of the team’s top prospects — Henry Owens and Deven Marrero, among others — await in the upper minors. That young talent, paired with Boston’s remaining veterans, forms the skeleton of a contending team.

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However, that skeleton still lacks some flesh in the form of high-ceiling starting pitching. Naturally, that need has given rise to rumors that general manager Ben Cherington hopes to bring back Lester when he reaches free agency at the end of the year. It would seem like the perfect plan: Loan Lester — who was likely headed for free agency anyway, after passing on Boston’s underwhelming four-year, $70 million extension offer in spring training — to a contender for two months, land a big bat in return, and then re-sign Lester (who’ll be the best left-handed arm on the free-agent market), combining the best aspects of being both a buyer and a seller. That Cherington traded Lester to Oakland, a team that probably can’t afford to keep him, made the scenario seem even more sensible, especially when laid out by a Red Sox source who told NESN’s Tom Caron that the club plans to pursue its former ace.

Before we delve into the team- and player-specific reasons why a Lester–Red Sox reunion scenario does or doesn’t make sense, though, we should examine the historical precedent for the trade-and-re-sign maneuver. According to transactions data from Retrosheet and MLB.com, parsed and provided by Baseball Prospectus, there have been 35 cases matching the broad strokes of Lester’s situation since 1978, when Toronto traded Rico Carty to Oakland on August 15, then re-signed him five months later. That’s almost exactly one instance per year, on average, of a major leaguer being traded in June, July, or August, then re-signing as a free agent with the team that traded him before (or at the beginning of) the following season. The most recent example is closer Francisco Rodriguez, whom Milwaukee signed in April 2013, traded to the Orioles two weeks before last year’s deadline, and inked again in February.

You can find the full list here, but I’ve included the most notable examples — the players who were traded in the midst of seasons in which they were worth more than one win above replacement player — in the table below.

So how did Henderson end up here, other than by playing long enough that almost everything was bound to happen to him at some point? And what does his presence say about the Sox’s chances of landing Lester? Current Mets general manager Sandy Alderson was Oakland’s GM on July 31, 1993, when the A’s (who finished 68-94 that season) traded Henderson to the Blue Jays for Steve Karsay and a PTBNL, whose name turned out to be Jose Herrera. Alderson was still Oakland’s GM on December 17, 1993, when the A’s talked Henderson into returning to Oakland on a two-year, $8.5 million contract. The 34-year-old Henderson had been enjoying one of his finest offensive seasons when he was traded, batting .327/.469/.553 before the deal, but he hit only .215/.356/.319 for Toronto, which won the World Series anyway.

Alderson recalls that it was possible for the A’s to re-sign Henderson because of what he describes as “unusual circumstances.” Obviously, there aren’t a lot of these guys. (Expanding the sample to players who were traded before a given season and re-signed the year after that turns up more names, but few prominent players aside from Cliff Lee, whose return to the Phillies represents the best-case outcome for Boston in the Lester negotiation saga.) The majority of the players who changed teams twice in this way were marginal performers, and Henderson stands alone as the list’s only true superstar, with a sizable lead in both trade-year WARP and WARP in the season after re-signing. If Lester finishes with his PECOTA-projected total of 4.4 WARP in 2014 and the Red Sox re-sign him this winter, he’d have the second-highest trade-year WARP of anyone on this table.

“We’d already traded him once,” Alderson says, referring to the 1984 swap that sent Henderson to the Yankees, “so that wasn’t the first time. Given the fact that he was from Oakland and had strong family ties there with his mother, having been traded to New York and brought back once, the possibility of bringing him back a second time wasn’t out of the question.”

Alderson notes that the likelihood of convincing a traded player to come back after so little time has elapsed “depends on the relationship that existed before the transaction, and the circumstances of the transaction, where if everybody sort of understands why it makes sense for a deal to be made, then I think there’s a greater possibility that the player can return. But if the relationship wasn’t terrific to begin with, or if there’s a misunderstanding or disagreement over the circumstances of the trade itself, then I think that also diminishes the chances.”

According to Alderson, conversations about bringing a player back as a free agent “rarely take place” before a deal goes down. (He doesn’t remember ever engaging in such a discussion with a player he planned to trade.) And once the transaction does become official, tampering rules prevent a player’s old team from making overtures while he’s still someone else’s asset. The result is some unavoidable uncertainty about where both parties’ allegiances lie, although both Cherington and Red Sox owner John Henry conveyed their appreciation for the homegrown Lester’s years of service before bidding him good-bye (and Henry went so far as to call Lester a “Red Sox forever,” supplying some fodder for the conspiracy theorists).

“There are a lot of forces at work in free agency that a club can’t always anticipate, and I think that’s probably why it’s so rare that a player does actually re-sign with a team that recently traded him away,” Alderson says. “Once you sever the relationship, you’ve got to be prepared for the player to move on, based on how the market reacts to free agency.”

Extracting extra value from a player you plan to re-sign by auctioning off two meaningless months sounds smart in theory, but like most open relationships, it’s much messier in practice.

Rockies GM Dan O’Dowd puts it even more bluntly. “When dealing with player trades, it is always difficult to squeeze the toothpaste back in the bottle once you have squeezed it out,” he says. “Even the best of intentions and world-class communications does not matter, in my humble opinion, unless your offer is higher than any other on the table.” Boston’s offer wasn’t high enough to lock up Lester when it had the table to itself, so it’s fair to wonder whether it will be when it has to share the table with every other interested team.

The player perspective largely jibes with what the executives say. Doug Glanville, a former major league outfielder and current ESPN analyst, agrees with Alderson that “the terms of the exit matter … a lot” and echoes O’Dowd’s belief about the power of the purse.

“Part of it is the cat-out-of-the-bag phenomenon,” Glanville says. “Most players that go into free agency get more money. Hometown discounts gets trumped.”

Glanville also stresses the psychological aspects of the decision. “It takes so much emotional energy to leave a long-term team relationship, and [it’s] worse when you didn’t initiate it,” he says. “Once you settle in and get a taste of leaving, [it’s] a lot easier to keep going and make more detached decisions.”

Thanks to their 2012 salary-dump deal with the Dodgers and their Clooneyesque commitment to avoiding long-term ties, the Sox, already a big-budget team, have plenty of cash to offer their erstwhile ace. Prior to acquiring Craig, only Dustin Pedroia’s reasonable contract remained on the books beyond 2015. To contend next season, the Sox will have to devote some of their payroll room to productive players, and Lester is one of only a few appealing pitchers whose services can be bought without raiding the farm system or the rest of the roster.

In light of their apparent need for top-of-the-rotation talent and their ability to afford it, their long relationship with Lester (who expressed a willingness to take less money to stay with the Sox), and the leaguewide trend toward more extensions and less roster turnover, the team’s failure to reach an agreement with Lester is strongly suggestive. Given how far apart their figures were, the idea that Lester and the Sox have an informal agreement to get back together seems far-fetched. And if the Sox aren’t willing to soften their hard-line stance against long-term contracts for 30-year-old arms, there’s no chance that they’ll match whatever bids Lester receives from less risk-conscious clubs.

This isn’t a Hendersonesque homecoming case. As one assistant GM opines, “It will be difficult for [Lester] to go back to Boston, both because of the acrimony [about his contract] and the fact that he actually makes his home in Atlanta. Put another way, there is nothing tying Lester to the Red Sox except memories — and his recent memories are not good.”

Gabe Kapler, another former major league outfielder and an analyst for Fox Sports, downplays the importance of the recent past. “I don’t buy lingering bitterness as a factor,” Kapler says. “Money is too powerful a variable.” However, he acknowledges that familiarity can make the heart grow less fond, thanks to “warts seen on both sides.” As effective as Lester has been this season, Boston’s front office got a good look at his uneven last two seasons, which must still be on Cherington’s mind. Kapler also notes that the prospect of greener grass and a new clubhouse culture can be enticing to a player who’s spent his whole career in one place, especially after he’s broken the seal, so to speak, by losing his chance to spend his whole career with one franchise.

Some Red Sox players are certain that Lester will be back, and some well-connected writers have heard that the Sox plan to “make a huge effort” to prove those players right. Other media members put the odds of a Lester–Red Sox reunion at 50-50, which seems like an overconfident estimate in any player’s case, let alone Lester’s, if only because of the fog of free agency that Alderson described and the number of competing bids that Boston would have to beat out.

We can’t say for sure that the Red Sox will or won’t re-sign Lester. However, we can say that if Boston brings him back, it will be in defiance of history — the history of players dealt at the deadline, and the team’s own recent history with Lester.