Whenever the Arizona Diamondbacks turn out to be the third team in a trade, I find myself wondering why they didn’t simply sit it out. The complexity of those transactions means there will nearly always be, if not a loser, a clear third team. Arizona has an unfortunate knack for being that team.

It began way back in December 2009, before the days of Kevin Towers, when Arizona facilitated a trade between the Yankees and Tigers by swapping, ultimately, Max Scherzer and Daniel Schlereth for Edwin Jackson and Ian Kennedy. That deal turned out fine for them, thanks mostly to a good deal they made less than a year later, flipping Jackson to the Chicago White Sox for Daniel Hudson and David Holmberg, a pair of pitching prospects. Holmberg, the younger and more remote of the two, has blossomed since joining the Diamondbacks system, and had an ERA just over 3.00 in 41 starts over the last year and a half, at Double-A.

Last winter, Arizona again leaped into the fray to help the Reds and Indians complete a trade centered around Shin-Soo Choo. They dealt away Brian Shaw and Trevor Bauer, and in return, got Tony Sipp and Didi Gregorius. Sipp, a left-handed reliever, is off their 40-man roster now, having been designated for assignment. Gregorius had a fine but uninspiring season as a rookie shortstop. Long viewed as a great defensive shortstop who would struggle to hit enough, Gregorius posted a perfectly respectable .252/.332/.373 batting line—not great, but better than the median shortstop. His defensive numbers, though, suggest that he had a very tough year afield. It already looks like the shortstop of the future in Arizona might be Chris Owings, not Gregorius.

So my eyebrow was arched before I even heard what, exactly, was the nature of the Diamondbacks’ involvement in the trade that sent Ryan Hanigan from the Cincinnati Reds to the Tampa Bay Rays Tuesday. I guess the correct way to state that is that my eyebrow is still arched (figuratively), and that we still don’t know the full and true nature of Arizona’s role. We know that they traded Holmberg to the Reds, and reliever Heath Bell to the Rays, and that they also included some cash to help Tampa defray Bell’s cost. We know that they acquired Justin Choate, a minor-league reliever, from the Rays, and that they’ll also acquire a player to be named later. Choate is a near-total mystery, though given Towers’ scouting reputation, that’s less of an indictment than it would be had several other teams landed him. Presumably, hopefully, for the sake of all our sanity, the player to be named will be of greater note, and will help explain this move.

For the moment, it looks like a deal predicated primarily on addition by subtraction, at least for Arizona. They were open about their intent to shift some of the money they had committed to spend on their relief corps to more essential areas, like a power bat at a corner position. In order to save some money on Bell, Towers scoped out an opportunity and pounced, even though it meant giving up a left-handed pitcher who could be a solid back-end starter by the end of 2014. Softening the blow of losing Holmberg is Arizona’s tremendous pitching depth, even from the left side. I’m not sure I would have made that sacrifice, but if the Diamondbacks can find a good way to spend the saved money (there are whispers of them seeking a power-hitting third baseman, which seem silly, because they have a graduating prospect named Matt Davidson who fits that profile; we’ll see), then Towers can end up looking smart.