It's happening.

Deals are being made. Breaking points are being reached. Welcomes are being worn out.

Changes are afoot.

You want to stay ahead? You better keep abreast. That Nationals trade Sunday was just the start of what's sure to be a league-wide reshaping of the bullpens.

The biggest waste, as baseball resources go, is someone who preserves a lead that doesn't matter. Every year at about this time, the contenders are in an arms race that the pretenders are all too happy to facilitate

Before the All-Star break, I looked at some of the top closers-in-waiting across baseball -- an exercise that was mostly theoretical -- but we're actually witnessing a changing of the guard in six bullpens.

Here's my take on each:

Cardinals

Most of us were ready to move on from Seung-Hwan Oh in mid-May, when it became clear his slider wasn't getting the swings and misses it did a year ago, but for manager Mike Matheny, it took Oh serving up walk-off three-run homer in the first game of the second half. To be fair, Matheny hasn't had a suitable alternative for most of the year, but in recent days, a couple of highly regarded Cardinals relievers have righted the ship in a way Oh hasn't.

One, Brett Cecil, finally got his opportunity Sunday after a string of 15 2/3 scoreless innings that put him back in Matheny's good graces. The lefty repaid his manager by allowing two earned runs in two-thirds of an inning, blowing the lead and taking the loss.

So now ... Trevor Rosenthal? "Has to be" was Matheny's response to the St. Louis Post-Dispatch, though the nature of the endorsement is unclear. I interpret it to mean Rosenthal is another option rather than the option, but he does have six straight hitless appearances with 10 strikeouts to no walks (which he credits to a mechanical change made from watching rookie Luke Weaver play catch) and now boasts a respectable 1.16 WHIP, not to mention a 2.15 FIP.

Nationals
Pecking order

Oh yes, the "big trade." I use quotation marks because I think we'll come to see it as a medium-size trade over the next couple weeks -- for the Nationals themselves, I mean. I can't believe that they believe their bullpen issue -- the Achilles' heel of what could be a juggernaut -- is resolved. Two arms are better than one, sure -- and the Nationals needed all the help they could get -- but neither Ryan Madson nor Sean Doolittle is a well-established, trusted closer.

In theory, it shouldn't matter. They've proven to be effective pitchers, each boasting a WHIP below 0.80 (a remarkable number regardless of role or era), and over time, a pitcher will pitch to his abilities regardless of role. But "over time" is only applicable to the theoretical, and the Nationals have two weeks to figure out whether or not they're in capable hands. If neither Madson nor Doolittle, given their limited histories in the role, takes to it right away, it's an invitation for Dusty Baker to keep experimenting, perhaps returning to one of the options that failed him in the past. And then what would have the Nationals really accomplished?

Again, they need all the help they can get, and the clincher for remaking their bullpen would be landing a trusted closer -- a Zach Britton or David Robertson or Raisel Iglesias type. Ultimately, it's what I think they'll do. In the meantime, I'd favor Madson to Doolittle since he throws right-handed, but he doesn't have the bat-missing ability of Doolittle and may be short-lived in the role either way.

Rangers

Who got the Rangers' first two saves in the second half? Alex Claudio. So who looked like the Rangers closer heading into Sunday's game? Alex Claudio! But then who worked the eighth inning with the score tied? Alex ... Claudio?

Oh.

Look, even if manager Jeff Banister were to make Claudio's coronation official, complete with a crown and a scepter and a banner and cake, it would probably be a tumultuous reign. He's maybe their fourth-best reliever. His rate of 6.1 strikeouts per nine innings would be bad for any reliever these days, but particularly in a role where a series of bloopers and bleeders could end the game in an instant, it's problematic. Granted, the strikeouts have improved of late, but enough that I could honestly say Claudio is better than Matt Bush or Jose Leclerc? No, not I.

And the plan at the start was to back off Bush for a couple weeks to get him right. In six June appearances, he has allowed one hit, striking out seven, so I still think it would be all too easy for the Rangers to turn back to him. Failing that, Keone Kela looked like the heir to the closing throne before hitting the DL with a sore shoulder in early July -- putting together a 1.23 ERA, 0.68 WHIP and 13.1 strikeouts per nine innings in his last 21 appearances -- and he's on the verge of returning.

Orioles
Pecking order

Zach Britton -- who, remember, placed fourth in AL Cy Young voting last year -- came off the DL June 5 but still hasn't returned to the closer role. There was an All-Star break in there, so we're talking a span of only five appearances, but still, he has had only one clean inning among those five appearances. And considering the two months he missed with a strained flexor tendon was a continuation an earlier DL stint, you have to wonder if he's still not quite right. This is the same injury that kept coming back to bite Wade Davis last year, after all.

Buck Showalter says Britton is getting closer to returning to the role, and maybe it'll happen tomorrow. But he's also becoming a hot trade commodity with the Orioles out of contention, with even the Dodgers -- home of Kenley Jansen, you may recall -- mentioned as a destination.

So healthy or not, Britton isn't assured a return to the closer role. It's much more likely than not, but not assured. And Brad Brach -- who has impressed with a 2.75 ERA, 0.86 WHIP and 9.6 strikeouts per nine innings this year -- isn't assured a return to setup duties. Given the possibility of either another DL stint or trade for Britton, Brach remains a player to stash in leagues where saves are scarce.

Tigers
Pecking order

You know who may be an even higher-priority lefty for contenders than Britton? Justin Wilson, that's who. Despite inheriting the closer role in mid-May and boasting a 2.29 ERA, 0.91 WHIP and 12.7 strikeouts per nine innings on the year, the 29-year-old still doesn't feel like he's fully established as a closer because the Tigers have provided him with so few opportunities. So there's no guarantee it's the role he'd be asked to fill with his new team, especially being a left-hander.

The Nationals are rumored to have interest -- and I presume he'd have just as much claim to the role there as either Ryan Madson or Sean Doolittle -- but the Rays are also a possibility, as are the Astros. Both of them already have closers. Wilson has another year of team control, so no guarantees the Tigers deal him at all. But there's plenty of smoke here.

And who would replace him in Detroit? The possibilities are uninspiring, particularly with Alex Wilson's pitch-to-contact ways catching up to him in recent weeks. Shane Greene, who came up as a starting pitcher with the Yankees, would probably be the front-runner, having put together a 3.00 ERA, 1.24 WHIP and 9.9 strikeouts per nine innings, but of course he'd suffer from the same lack of opportunities that Wilson has. 

Giants
Pecking order

Sam Dyson isn't all the way back to where he was last year, but by leaning on his cutter since joining the Giants, he has made himself into a respectable reliever again, compiling a 2.03 ERA, 1.05 WHIP and 8.8 strikeouts per nine innings over his last 12 appearances. He's also a perfect 4-for-4 in save chances since stepping in for the injured Mark Melancon. He was 0-for-4 with the Rangers earlier this year.

Has he rehabilitated his image enough for the Giants to flip him to a contender? Probably not to fill a high-leverage role, and the return may not be great enough if that's the case. Mark Melancon, meanwhile, has begun a throwing program, but seeing as he's dealing with a strained elbow, a contender would need some assurances before making a move for him. Quite simply, we're running out of time.

So this situation is pretty straightforward, I think: It's Dyson for now, but probably not for long. Yeah, maybe Melancon misses the rest of the season, but more than likely he'll return at some point and relegate Dyson to setup duties. Still, his return isn't so close that you shouldn't gobble up as many saves as you can in the meantime, even if they're of the shakier variety.