I have to start with a massive tip of the SnakePit hat to Ben Lindbergh of Grantland, who did the work of tracing the lineage of every players on every team's 40-man roster, to find out from whom they originated. I'd likely have got bored and given up half-way through Baltimore. Lindbergh was clearly made of sterner stuff, and persevered: you can check out his article here, and see how Cy Young winner Corey Kluber's presence on the Indians goes all the way back to a deal made almost a decade before he was born.
But I figured it'd be fun to take a look at the Diamondbacks entry in more detail. There are two ways in which players can be connected. Most obviously, they "can be a product of the same linked sequence of trades." If we trade player X for player Y, and then player Y (even if other players are involved too, on either side) for Player Z, then players X and Z are linked. The other way is through compensatory draft picks. If we failed to sign Player X as a free-agent, and got a draft pick in compensation, which we used to select Player Y, then players X and Y would also be considered as linked. And with that, here we go... I've bolded the names of the players in the chain, to make it easier to see them.
1) November 8, 1995: GREG AQUINO signed by Arizona as an amateur free agent.
Aquino may be one the very first Diamondback ever - it's the first recorded in B-R.com's transaction logs, with the second being catcher Rod Barajas, signed the following January, kicking off the first year we took part in the June draft Aquino's signing was close to two and a half years before our first game, and almost a year before we signed Travis Lee. Aquino originally called himself Gregory Valera, and turned out to be a year older than claimed, but still made it to the majors in 2004. He appeared in 111 games out of our bullpen, with a 4.93 ERA, and was last seen with the indie ball Sugarland Skeeters in 2013.
2) November 25, 2006: GREG AQUINO, Johnny Estrada and Claudio Vargas traded by Arizona to Milwaukee for Doug Davis, DANA EVELAND and Dave Krynzel.
The next link in the chain is Eveland, who was a side-dish in what was mostly a swap of catcher Estrade for starting pitcher Davis - a trade which worked out better for the Diamondbacks than the Brewers, I think. Eveland's Arizona career didn't start well, as he allowed three runs in one-third of an inning on April 24, 2007. His solitary start for us, on September 1 the same year, wasn't much better, since he was charged with five earned runs and didn't get out of the third inning. His 14.40 ERA with Arizona is the highest of any pitcher to throw 5+ innings with us, just edging Kerry Ligtenberg's 13.97, but Eveland is still about, pitching solidly for the Mets this season (2.63 ERA in 27.1 IP).
3) December 14, 2007: DANA EVELAND, Brett Anderson, Chris Carter, Aaron Cunningham, Carlos Gonzalez and Greg Smith traded by Arizona to Oakland for DAN HAREN and Connor Robertson.
After winning the division in 2007, Arizona tried to improve the rotation by trading for the A's Haren, sending a slew of young prospects off to Oakland. Their subsequent results were mixed: Eveland, Smith and Cunningham have been close to replacement level since, but Anderson has been good (when healthy), and Gonzalez, of course, is a two-time All-Star and three-time Gold Glover - albeit after then being traded on from Oakland to Colorado. Haren, meanwhile, pitched well (ERA+ 125) but the D-backs still failed to retain their division title, starting a tailspin that would end in 2010 with a 65-97 record.
4) July 25, 2010: DAN HAREN traded by Arizona to Anaheim, for a player to be named later (TYLER SKAGGS), Patrick Corbin, Rafael Rodriguez and Joe Saunders.
This is probably the point in the tree where you go "Ah-hah!" and see where this is going. With the D-backs well out of contention by the All-Star break, they opted to part ways with Haren and rebuild, even though he was under team control through 2013. At the time, "The deal drew immediate skepticism from those within baseball and those who cover it, some of whom called it a salary dump and were critical of the quality of players received," though that was before Skaggs was known as the PTBNL. But it does perhaps show the danger in kneejerk evaluation of any swap involving future prospects, as it now seems a much more balanced trade.
5) December 10, 2013. TYLER SKAGGS traded by Arizona to Anaheim for A.J. Schugel and MARK TRUMBO. A lot of other stuff also went on in that trade, not relevant here. :)
And so, we arrive at Trumbo, whose origins as a Diamondback go back almost 20 years, to the first player recorded as having been signed by the team. Curious for Skaggs to end up back where he came from, after what amounted to 3.5 years in the desert [heck, even Jesus only had to spend 40 days there...] Like step 3, this was a case of the team trading future potential for more immediate production: we'll see how this one works out, but largely thanks to the "other stuff" in the shape of Adam Eaton, early returns don't look good for Arizona. Will the chain end here, or is this going to run on further, with Trumbo being dealt before he reaches free-agency?
[The above in graphical form, click to enlarge in new window - image through Grantland.com]