Though the Mets need a bat most of all, their acquisition of Tyler Clippard makes good sense. By fielding-independent numbers, their bullpen has been middle-of-the-road so far this year, and the returns of Jenrry Mejia and Bobby Parnell might not be enough to push this bullpen into a strength as the end of the season approaches. Mejia’s post-season ban also creates a need, should they win the wild card and play extra baseball.

The prospect going back to the Athletics may not move the national needle much. 20-year-old Casey Meisner has spent the last 100+ innings striking out fewer than a batter per inning, and our own Kiley McDaniel wasn’t effusive in praise when he ranked Meisner the 22nd-best prospect in the Mets organization:

22. Casey Meisner, RHP Video: Meisner is a 6’7/190 righty that went in the 3rd round in 2012 out of a Texas high school. He sat 88-92 in high school and is now 90-94 mph, with good downhill plane; his curveball and changeup are both around average now and flash better, with so much projection it’s hard to say exactly what Meisner’s upside really is. He’s a solid athlete for his size and is pretty coordinated, so the typical super-lanky pitcher command concerns haven’t applied yet.

Because of the age and frame, maybe there’s more velocity coming. Because his two secondary pitches flash better, maybe there’s an actual major league starter coming. Because of these two facts, Meisner was one Mets player the Brewers were interested in if the two were going to complete a Gerardo Parra deal.

Interesting that Casey Meisner is the one to go in this deal. I’m told he was the Mets pitchers Brewers wanted in Parra deal.

— Marc Carig (@MarcCarig) July 27, 2015

There’s enough to dream on when it comes to Meisner, but this acquisition probably says the most about the Mets’ prospect depth in general. Though that writeup above was for the 22nd-best Met prospect, it was also for the fourth-best 40 Future Value player in McDaniel’s rankings. Here’s the writeup for the Padres’ fourth-best 40 FV right-handed pitcher:

12. Justin Hancock, RHP Video: Hancock gives scouts two looks, so takes on him vary based on what version scouts saw of him. At his best, Hancock sits 92-94 mph with an above average to plus changeup and an average breaking ball with enough command to project as a back-end starter. On other days, the off-speed and command is more fringy than average and he looks like a Burch Smith-type swing man or middle reliever. He’ll go to Double-A or Triple-A next year and with some consistency could turn into a big league option by the end of the year.

Obviously those aren’t the same guys. But they aren’t far from each other, and yet one was his team’s 22nd-best prospect, and the other was his team’s 12th-best. Hide the team and player names on these situations, and it’s a no-brainer to say that you’re more likely to trade away the 22nd-best guy. The Mets had depth and they used it to improve their chances.

But former General Manager Dan O’Dowd pointed out on the MLB network that this calculus works in the other direction, too. If teams see that your cupboard is bare beyond your top two or three prospects — say, perhaps the situation in Baltimore — they’re less likely to think there’s a fit there. They are less likely to want to deal for *your* 20th-best prospect, but they might also be less likely to trade for your 14th-best prospect because of the idea that your system is barren.

Some feel that Sandy Alderson hasn’t done a lot of trading as a General Manager in New York. But by not trading, he’s improved the depth of his system. Which makes it easier to make small trades to improve the team in-season, when you have more information about how competitive your team is going to be.