Needless to say, right-handed relief pitching is perhaps the most-moved asset during July. Last year, things got started with a swap of righties Carlos Marmol and Matt Guerrier, with Mitchell Boggs, Francisco Rodriguez, Guillermo Moscoso, Jesse Crain, and Jose Veras also moving in July. The August revocable waiver trade period saw John Axford and Vic Black change hands.

Significant movement has already occurred this year, of course, with Ernesto Frieri and Jason Grilli swapping jerseys. Since that time, quality arms like Joakim Soria, Huston Street, and Jason Frasor have gone to contending clubs. That does not mean that the action is over on this front, however. Let’s see who else might be available:

Current/Former Closers

Koji Uehara (Red Sox), Joaquin Benoit (Padres), Jonathan Papelbon (Phillies), Steve Cishek (Marlins), Brad Ziegler (D’backs), Chad Qualls (Astros), LaTroy Hawkins (Rockies), John Axford (Indians), Grant Balfour (Rays), Jim Johnson (Athletics)

• If the Red Sox decide to market Uehara, rather than holding onto him and either making a qualifying offer or extending him, he would likely be the best arm available. Uehara is the kind of dominating closer that can add huge value down the stretch and in the postseason, and would figure to draw substantial interest from any team with an eye on October. He is owed very little this year, and would be a pure rental.
• Benoit has somewhat quietly been nothing short of dominant over the last two years. He is owed $8MM next year and comes with a $8MM club option ($1.5MM buyout) for 2016. Of course, San Diego has indicated that it will only move its newly-minted closer for a big return, having already dealt away Street.
• Papelbon has actually been quite a bit more effective than one might expect, given all the negativity surrounding his contract and stay in Philadelphia. The 33-year-old’s velocity is down, but so is his ERA (1.91). And while the contract still looks bloated, it no longer seems entirely untradeable. Papelbon’s annual rate is $13MM both this year and next, and he comes with an achievable vesting option for the same price in 2016 (vests with 55 games finished next year or 100 total between 2014-15).
• Cishek is an arb-eligible 28-year-old playing on a $3.8MM Super Two salary. His ERA is at a career-worst 3.32 — he’s allowed less than three earned per nine in every full season of his career — but his FIP is at a career-best 2.06. Though it seems that the Marlins are unwilling to move him, his swiftly rising salary means that you can’t rule out the possibility if the right offer came in.
• Though he has not spent much time in a closing capacity, Ziegler does have some experience there after logging 13 saves last year. More importantly, the 34-year-old has not seen his ERA land above its current 2.84 level since the 2010 season. He is striking out more batters than usual (7.8 K/9), while his walk totals remain in line with his career numbers (3.0 BB/9)  and he continues to induce a ridiculous number of ground-balls (66.4%). Owed a reasonable $5MM next year, and coming with a $5.5MM club option ($1MM buyout) for 2016, his contract also looks pretty good — although that is also why Arizona is reportedly inclined to keep him.
• Qualls and Hawkins, both veterans of the league, are currently working as closers but would almost certainly be dropped in the pen hierarchy on a contender. The pair has been effective over the past two seasons, and both play for obvious sellers. But the Astros have indicated that they are hesitant to move the more desirable Qualls (who they control for two more years), while the Rockies could also opt for stability rather than a meager return on Hawkins (who will be a free agent and has struck out just 4.4 batters per nine).
• Then we arrive at the highly-paid, deposed closers: Axford, Balfour, and Johnson. The 31-year-old Axford comes with control, but could be a non-tender candidate again this year. Though he is the only one of this trio that has been reasonably productive this year (3.23 ERA, 11.1 K/9 vs. 6.0 BB/9), little in the way of rumors suggest that he is being asked about or shopped. Meanwhile, Balfour and Johnson are both grossly overpaid and underperforming, and could surely be had for a meager return, with their current teams eating most or all of their salaries. (The latter, of course, is in DFA limbo at the moment and could become freely available at league minimum in short order.)

Set-Up Men

Burke Badenhop and Edward Mujica (Red Sox), Juan Carlos Oviedo (Rays), Scott Atchison (Indians), Ronald Belisario and Javy Guerra (White Sox), Casey Fien and Jared Burton (Twins), Neftali Feliz (Rangers), Jose Veras (Astros), Carlos Torres and Daisuke Matsuzaka (Mets), Carlos Villanueva (Cubs), Tim Stauffer and Blaine Boyer (Padres), Matt Belisle (Rockies)

Among these players, only Belisario, Guerra, Torres, and Fien come with control extending beyond 2015. Neither of the ChiSox hurlers has been that good, however, and the Mets and Twins will probably be in no rush to move Torres and Fien since they come with multiple years of control and should remain fairly inexpensive.

The other arms are purely short-term options who could help with depth down the stretch and (in some cases) next year. Feliz has had his struggles and will not be cheap as a project arm, and probably will get a chance to regain his form in Texas. Otherwise, Badenhop is probably the prize of this group after Fien; he has been steady for the third straight year and shouldn’t be expensive (in dollars or prospects) as he prepares to hit the open market. Belisle could be an intriguing buy-low rental, as his numbers continue to be inflated by pitching at Coors Field, though he has also seen his FIP rise to 4.12 on the back of a troubling dip in his strikeout numbers against recent seasons (6.4 K/9 this year after averaging 7.9 K/9 over prior four campaigns).