Here's a list of every former Pirate currently on another team's active roster. I'm sure I missed a few. Let me know in the comments. This idea, like so many bad ideas, comes from McCovey Chronicles.
Cubs: David Ross. Sometimes I think about how David Ross collected 119 plate appearances for the Pirates in 2005, and it seems strange, like the fact that something called "Arkansas" is a state or how bookstores frequently contain "teen vampire fiction" sections. Ross passed into and out of Dave Littlefield's hands like it was nothing, but then he got a reputation for working well with pitchers, and baseball let him work until he was old as dirt.
Cardinals: Brandon Moss, Eric Fryer. Moss isn't the same player he was in his 2012-13 breakout with the A's, but he still hits just enough to be sort of useful if you shield him from lefties. He's now 32.
Brewers: Keon Broxton lucked into a great situation when the Bucs traded him to Milwaukee this winter. The Brewers have a gaping hole in center field that got even gaping-er in Spring Training when Rymer Liriano injured his face. Broxton, though, has gone 1-for-11 with seven strikeouts so far.
Reds: Ross Ohlendorf is still out there, and this weekend, his presence on the Reds' roster helped the Pirates to a degree Ohlendorf rarely could when he was actually with the team. The Reds' current roster also features former Bucs Triple-A vets Jumbo Diaz, Blake Wood and Ivan De Jesus.
Mets: Neil Walker, Antonio Bastardo. This offseason, the Mets nabbed two useful players from the 2015 Pirates, although both are off to reasonably slow starts in New York. Walker is blocking another former Pirates product: prospect Dilson Herrera, who headed to the Mets in the Marlon Byrd trade and is currently with Triple-A Las Vegas.
Braves: Jason Grilli missed a chunk of last season to an Achilles tendon and is back healthy. His average fastball velocity is now below 92 MPH, however, and he's struggled in his first three outings.
Phillies: Charlie Morton, Jeanmar Gomez. Gomez is the Phillies' closer, or something like it, right now. Think about that. Wrap your head around it. You can't.
Nationals: Oliver Perez is one of several former Pirates lefties who flamed out as starters but have remade themselves in the bullpen. Paul Maholm has to be wondering how he missed the gravy train. Perez is now 34 and in his 14th season in the league, and he's all but guaranteed a 15th season, since he's signed through 2017.
Marlins: Bryan Morris. Among life's great mysteries: How Bryan Morris has a 2.87 career ERA and a -1.4 career fWAR. Despite peripherals that continue to suggest he's really isn't very good, Morris continues to soldier on in the Marlins' bullpen.
Dodgers: Joe Blanton turned his brilliant stretch run with the Pirates into a $4 million deal in LA. Go look at Blanton's stats last season. I knew they were good, and I was still shocked how good they were.
Giants: Javier Lopez, more proof that lefties are forever. I know we've played this game before, but quick -- name the two players the Pirates got for Lopez back in 2010. The trade made sense at the time. A situational lefty wasn't a luxury the Bucs needed then. But Lopez has been amazingly effective in five and a half seasons since.
Rockies: Chad Qualls wasn't very good in 2012, the year the Pirates acquired him for their stretch run. But he's always gotten ground balls, and look what's happened to his strikeout and walk numbers in the past four years. Oh yeah, Chad Qualls likes that a lot.
Red Sox: Brock Holt. Mark Melancon's fWAR since the Red Sox traded him to the Pirates: 6.1. Brock Holt's since the Pirates traded him to the Red Sox: 4.7. Joel Hanrahan didn't work out in Boston, but the Hanrahan deal was much less lopsided than it might have been, thanks to the fact that Holt turns out to be a pretty good player.
Rays: Dana Eveland, Steve Pearce. Yes, Dana Eveland used to play for the Pirates, and yes, he currently plays for the Rays. As for Pearce, it's a shame the Pirates never really bothered to try to harness whatever they had in him; I remember not understanding it at the time, and looking over his stats, I still don't. At worst, he's versatile defensively, and good enough to not hurt you offensively. At his best, he punishes lefties and is an above-average hitter overall.
Orioles: Pedro Alvarez, Vance Worley. Alvarez is off to a 1-for-15 start in Baltimore. Worley, meanwhile, got the gig he couldn't hold onto in Pittsburgh, making the O's roster as their fifth starter.
Blue Jays: Jose Bautista, Russell Martin, J.A. Happ and Jesse Chavez. Bautista's loss still stings a bit -- not only did the Blue Jays get lucky with their low-cost pickup of Bautista in 2008, they correctly doubled down on their investment by signing him to an extension that now looks like a bargain. Six years after his breakout, he's still getting paid prices the Pirates could have afforded. Add Bautista to Martin and Happ -- two players the Jays signed away after the Bucs helped get their careers on the right track -- and there's a ton of former Pirates talent in Toronto.
Indians: Marlon Byrd, Rajai Davis. Byrd was in the itinerant-journeyman phase of his career before he blew up in 2013. Two and a half years after the Bucs acquired him for their stretch run that season, he's back in an itinerant-journeyman phase, having joined the Indians on a minor-league deal. Davis, of course, was one of the players in the Matt Morris deal, a trade for a contract so bad that no one's even bothered complaining about the fact that one of the players the Pirates gave up is still productive nine years later.
White Sox: Zach Duke. There's also Jerry Sands, who never technically played for the Bucs. It's not clear what got into Duke with the Brewers in 2014, but it seems to be gone now, as he walked far too many batters last year and hasn't pitched especially well yet this season. It's strange, though, that he briefly had a nice post-Pirates career at all, even if it was as a reliever.
Tigers: Justin Wilson. After spending one year in New York, Wilson continues his career as a solid lefty reliever in Detroit. The Pirates could still use him, but the player he netted them in return -- Francisco Cervelli -- has more value.
Royals: Edinson Volquez, Joakim Soria. Also Chris Young, who was once a Pirates prospect but never played for them. Volquez and Soria are on the small-market Royals because they commanded prices on the free agent market that the Pirates were unwilling to pay. I didn't disagree with the Bucs' decision to let either player walk -- if in fact they do possess the ability to rehabilitate pitchers' careers, it makes sense for the Pirates to cycle through them rather than paying market prices for the reclamation jobs they've already done. But it's interesting that two of those pitchers have gone to a fellow small-market team.
Astros: Erik Kratz. Kratz's big-league career -- which now spans seven years and five teams -- began with the Bucs back in 2010. Quick, name the other three catchers the Pirates employed that year. Ronny Paulino, you say? Nope.
Athletics: John Axford. Axford was a Pirate for about five minutes in 2014 before heading to Denver. I like to think he's the kind of guy who solicits high-fives for going to Colorado the year after marijuana was legalized and posting a 4.20 ERA.