“In the second half, the pitching is probably more an area where we’re going to take a hard look at.” — Mike Hazen

Yesterday, we discussed some of the names the D-backs might look at, as alternatives to Manny Machado, now a Dodger. But there’s no reason the team has to spent its limited trade chips on a position player, if better value is to be found on a pitcher. GM Mike Hazen, as usual, kept his cards close to his chest, saying only, “We have a strong team as it is. If the right fit comes along, we’ll still evaluate that and not rule any of those things out. But we’re going to be mindful of the overall talent that we’ve given up so far.” With that in mind, let’s see where the team might need a hand, and who might be available.

Relief pitching

The Diamondbacks bullpen has been excellent this season, by most metrics. By bWins Above Average, it trails only the Cubs in the NL and at 2.85, the Arizona relief corps has the lowest ERA in the league. So this might not seem in need of any help. But if you take defense out of the equation, the picture changes. Their fielding-independent ERA (FIP) is more than a run higher, at 3.96, ranking only seventh-best. Their strikeout rate is the worst in the league, being the sole team whose bullpen is fanning fewer than eight per nine innings (7.71). And Arizona’s relievers leave 81.3% of runners on base, a number which may increase in the second half toward league average of 72.9%.

There’s therefore room for improvement, and potential upgrades are available, according to Hazen: “It would seem that the bullpen is probably the area that has the most supply.”

Left-handed relievers

With three southpaw relievers - T.J. McFarland, Andrew Chafin and Jorge De La Rosa - currently in the bullpen, Arizona would initially appear well-stocked. But De La Rosa has been far from impressive this year (ERA 4.78, FIP 5.83). McFarland is a prime candidate for regression, with a FIP more than double his actual ERA (1.81 vs. 3.68), mostly due to his terrible strikeout rate of 5.68 per nine innings. Among 160 MLB pitchers with 50+ innings so far, that ranks McFarland... 160th, below even team-mate Matt Koch, who is 159th. And Chafin, too, has seen his ERA suppressed by good luck with fly-balls: he hasn’t allowed one to leave the park in 34 innings of work, behind just Zack Duke (34.2 homerless IP).

Jack ran his eye over a number of left-handed bullpen options last week. He notes the paucity of credible options from the left in the minor-league system, so it does seem any upgrade is going to have to come from outside. I thought I’d take a purely objective look for possible candidates, so cranked up the Baseball Reference search tool. I wanted left-handed relievers, with 20+ IP of work, on teams likely to be sellers at the deadline (below 15% playoff odds per Fangraphs). The last could certainly change: the Nationals, for example, still get a 59% chance of the post-season, despite being at .500. A quick losing streak, and the likes of Sean Doolittle and Matt Grace could be on the market.

For now, however, the above conditions gives us the table below of 17 potential names, in ascending order of FIP. The final column lists the season after which they will become free-agents (including any options), so we can get a feel for whether they are rentals or longer-term acquisitions. Players’ names link to their B-R.com pages, so you can check out their splits or more detailed stats.

[Update: We can cross Hand off, as he was traded to Cleveland this morning] Going by previous Mike Hazen acquisitions, non-closers would seem more likely to be targets. Of the half-season rentals, former D-back Duke stands out. Over the last five seasons, he has been among the most effective of left-handed relievers, with an ERA+ of 137 since the start of 2014. Luis Avilan is another possibility, whose FIP is below his ERA. and Avilan’s K-rate of above 25% would bump up the team’s stats in that category. There are a few longer-term options as well, if the team wanted someone to partner with Chafin, who is under contract through the end of 2020.

One name mentioned in connection with the D-backs, but not on the list above, is Zack Britton of the Orioles. He had a torn Achilles tendon, and so has only pitched 14.2 innings this year. ESPN’s Tim Kurkjian thinks he’d be a good fit: “If they can go get Zach Britton, who I was told was this close to being really, really good again, that would be a gigantic move for the Diamondbacks.” So far, Britton has not been up to his usual standards, walking nine batters already, but with a 241 ERA+ since 2014, his ceiling is almost unsurpassed among left-handed relievers, and he’s also a free agent at the end of this year.

Right-handed relievers

Thanks, but we’re good.

With Yoshihisa Hirano, Archie Bradley and Brad Boxberger, we have a trio I think are capable of standing beside anyone in the league. If further help is needed, Silvino Bracho would be the first name on the list. He appears finally to have figured things out this year, with an ERA of 2.20, a FIP below two (1.90) and 22 strikeouts in 16.1 innings. It’s just a case of Hazen and Torey Lovullo deciding at what point down the stretch, depth becomes less important than talent. It would not surprise me if the team perhaps went from a 4:3 RH/LH configuration in the bullpen to 5:2, dropping De La Rosa and permanently adding Bracho. Jimmy Sherfy, Jake Barrett and Braden Shipley have all also seen major-league innings this year.

This seems to make an external addition feel rather unlikely, though not impossible. For example, according to Paul Gambadoro on the radio today, the D-backs are interested in the A’s Blake Treinen. [Though are the A’s in sell mode?] He was an All-Star this week, and is under team control through the end of 2021, so would slot into the bullpen next year, after the departure of Boxberger. For completeness, here are the right-handed relievers listed by MLB Trade Rumors among their top 75 trade deadline candidates. I must confess, the idea of bringing Rodney back, purely for troll purposes, has strong appeal... Hell, bring back Tyler Clippard, Brad Ziegler and David Hernandez too, and party like it’s twentysomething.

Starting pitching

Arizona’s starting pitching has not been as much of a strength as the bullpen. At 4.11, our rotation’s ERA is fractionally worse than league average (4.09). Although if you take off the five starts by Shelby Miller and Kris Medlen in which their ERA was 12.32. the figure for everyone else across their 92 starts drops to 3.81, which would be fifth in the league. With Miller likely out for the foreseeable future, it seems likely the team will lean on Clay Buchholz in the second half. The depth thereafter is perilously thin: as mentioned above, Koch’s K-rate is a red flag for success and after that... Well, we did just re-sign Barry Enright, I guess?

However, with 65 games left, how many starting pitchers do we need? Looking at the post-break numbers over the previous decade for Arizona, the answer is between seven and nine, though the load is not evenly distributed. For example, last year, that included one-offs by Shipley + McFarland, and four by Anthony Banda, as well as the “regular” rotation of Zack Greinke, Patrick Corbin, Robby Ray, Taijuan Walker and Zack Godley. On that basis, Arizona will need more than Koch on standby to get through the rest of the schedule, though likely not for many starts. Here are the second-half starts made by pitchers outside the “front five” and “front six” each season of late:

2017: Beyond front five = 6; beyond front six = 2

2016: 16, 10

2015: 12, 6

2014: 5, 2

2013: 8, 5

2012: 11, 5

2011: 7, 4

2010: 6, 3

2009: 11, 5

2008: 5, 1

That averages out at 8.7 games per season needed from pitchers outside the front five, and 4.3 outside the front six. Not a large number, but in a potentially tight race, those starts could become significant. There’s definitely scope to upgrade a rotation spot anyway, probably pushing Buchholz down to the #6 spot, with Koch becoming the #7. Though that may depend on Godley sustaining the good performance his last couple of starts in the first half. With Corbin becoming a free-agent at the end of this season, I see no reason this necessarily has to be a rental either, as we’ll have a slot needing to be filled in the rotation next year as well. Here are the trade candidates listed by MLBTR, rentals shown in bold.

Much the same issues are likely to hamper any significant trade for the D-backs, as was the case with regard to Manny Machado. There are limited resources with which the team can part, and injuries to top prospects like Jon Duplantier and Daulton Varsho do not help. The projection systems aren’t very bullish on Buchholz’s numbers for the rest of the season, and if that is the case, then it wouldn’t take much for any new arrival to be an improvement. A key factor will be on what Mike Hazen sees as the window of competition for the team. If it’s only this year, then using our resources to get a better pitcher for the remainder of 2018 would make more sense than someone who’ll still be here outside the window.