I thought Evan Longoria would be a Ray for life, as he's the biggest star they've had in their franchise's brief history and his contract, which runs through 2022, didn't seem unreasonable at the time that he signed it. Alas, it wasn't meant to be, as his dip in performance made him tough for the low-payroll Rays to carry, and he's now a member of the San Francisco Giants in a deal that didn't bring much talent back to Tampa Bay.
The Giants have to hope they're getting the 2013-16 version of Longoria, who averaged 4.5 fWAR over those four years and never dipped below 3.3 in any of those seasons, but who saw his offense fall to the lowest levels of his career even as home runs remained high across MLB. Longoria was once a patient hitter, drawing 60 unintentional walks in a season four times, but last year that dipped to 43 and a career-worst .313 OBP along with a .424 slugging percentage that marked the second lowest of his career.
Longoria has been durable, playing in 156 or more games in each of the last five seasons, but he's just not the player he was a few years ago. Even his batted-ball data from Statcast in 2017 was consistently below the median, whether it's average or maximum exit velocity or the rate of Barrels (an MLB stat for balls hit with an exit velocity and launch angle likely to result in hits).
His performance was better in 2016, enough that I can understand a team hoping they're buying low on Longoria or that the minor thumb, foot and neck injuries he played through this past season were a factor. Still, there's a lot of risk here that he's past his peak and won't play well enough to justify the $86 million he's guaranteed over the next five years.
That said, the Giants couldn't even get replacement-level offense from third base in 2017, with their third basemen posting an aggregate .216/.268/.300 line. Even if Longoria just repeats what he did last year, San Francisco would still be at least two wins better off. That was by far the worst output the Giants got from any position, so the deal directly addresses their biggest weakness. There's also an addition-by-subtraction aspect to the deal, as they shed Denard Span, who was the worst defensive center fielder in baseball by defensive runs saved and the second-worst by UZR, off the field and the roster. That also frees up an outfield spot for the Giants to add a free agent like Lorenzo Cain, the top-ranked position player among free agents this winter, who would be something like a five-win upgrade given Span's awful defense last year.
In exchange, the Rays get good ol' Salary Relief, although some of that is offset by Span's contract, which pays him $11 million this year plus a $4 million buyout on a mutual option for 2019. Span might be a useful player again in an outfield corner; the Rays are already set in center field with Kevin Kiermaier, but Span would provide more offense than any of their in-house options for left field.
The Rays also added 2013 first-round pick Christian Arroyo, because the Rays love nothing more than to acquire shortstops who can't actually play short. He can hit but lacks patience or power and still hasn't settled into another position, although I don't see any reason he'd be unable to handle second base. There's a good chance he ends up an average everyday player at second because he'll hit for enough average to make up for the lack of secondary skills.
Finally, the Rays also received two fringe A-ball arms. They got lowercase-g giant lefty Matt Krook, who is frequently hurt and walked 16 percent of batters he faced in High-A en route to posting a 5.12 ERA, and right-hander Stephen Woods, who walked 13 percent of the batters he faced in Low-A as a 22-year-old, thanks to a long arm action. Both are closer to organizational depth than real prospects.
If the Rays get anything beyond relief from Longoria's contract, it's that they now have a spot open for their top position-player prospect, shortstop Willy Adames, who has performed well for his age at every level, hitting .277/.360/.415 as a 21-year-old in Triple-A last year. The Rays have long been higher on his defensive abilities at short than the rest of the industry (where views are mixed on whether he can stay there), but this would allow them to move him to third base and bring him to the big leagues in late April. They also could install Adames at short and slide Matt Duffy -- acquired from the Giants in a previous deal -- to third base, giving up shortstop Adeiny Hechavarria's defensive value. Hechavarria is a free agent after 2018, so they could also play Adames at third for the time being and then return him to short after the season.
Moving Longoria at least gives the Rays flexibility now and avoids blocking their top hitting prospect, while giving them the potential to add players or lock up some of their own young players once Span moves off the books.