Analyzing the Arizona Diamondbacks acquisition of J.D. Martinez

The problems

While the Diamondbacks’ offense has generally been solid this year, there have been a couple of obvious vulnerabilities. Firstly, there’s their struggles dealing with left-handed pitching. Arizona ranks 14th in the National League by OPS against LHP, with a line of only .223/..287/.373, a .660 OPS. We saw in the series against the Dodgers how that could be exploited, and how badly our hitters struggled against the Los Angeles trio of left-handed starters, Clayton Kershaw, Alex Wood and Rich Hill. Presuming we get through the wild-card game, we’d likely see them again in the Division Series (they’re 7.5 up on the Nats), so fixing that matters.

As mentioned in our article this afternoon looking at a potential deal, the left-field position for the D-backs has also been a bit of a black hole in terms of production this year, ranking near the bottom in the league. The injury to Opening Day starter there, Yasmany Tomas, obviously didn’t help things, but since then we’ve been running out Daniel Descalso and Chris Herrmann, both of whom are considerably better suited to bench roles. With Tomas’s return no longer in the foreseeable future, his groin tendinitis having been reclassified as a strain, four weeks after hitting the DL, the impetus for improvement increased.

The solution

Martinez is in his seventh major-league season, having originally been drafted in the 20th round by the Astros. He was actually released by them towards the end of spring training in 2014, and signed with the Tigers, where he has blossomed. Since then, he has averaged close to five bWAR per 650 PA, with a line of .300/.361/.551 and 99 home-runs in 1,697 PA. Over that time, his .912 OPS ranks ninth in the majors (min. 1,500 PA), and his OPS+ of 147 is very comparable to that of Paul Goldschmidt, who sits at 152 for the same period.

In his first season with Detroit, Martinez was mostly a left-fielder, but since then has played almost exclusively in right. It remains to be seen which corner he’ll occupy for the Diamondbacks. We could move David Peralta back to left, if the team wants to keep Martinez in his more customary spot. He grades as somewhat below average at both positions. UZR/150 has him at -4.7 in LF and -5.9 in RF. However, Peralta’s numbers suggest he’s much better in right (+5.7) then left (-5.9). so it wouldn’t surprise me if he stays where he is, and Martinez moves back into left-field. That would let both play their best positions.

Martinez has also hit left-handed pitching very well throughout his career, with an OPS 88 points higher than against right-handers. He has surprisingly few PAs against southpaws this year - only 45 - but the numbers are eye-popping: 18-for-38 with six home-runs. That’s a line of .474/.556/1.105, for a 1.661 OPS. For context, he could get absolutely nothing over his next 45 PA there, halving his OPS, and Martinez would still be ahead of what Paul Goldschmidt has done against lefties this season (.826 OPS).

The cost

Nothing comes for free, and the services of J.D. Martinez for the remainder of the season are no different. James estimates the financial cost will be $4.82 million the rest of the way. That’s in the ballpark of what flexibility the team had in terms of adding payroll, so it’s not clear if there will be any further room for additions to the roster, such as extra bullpen arms. There are some fans hoping that Martinez could end up re-signing here as a free-agent, but he’s going to get a VERY large deal, and it would take Ken Kendrick to open the wallet in an unprecedented way before that could even be considered.

There’s also the question of the prospects to be considered: Dawel Lugo, Sergio Alcantara, and Jose King. Where about were they on the pre-season prospect rankings? [Bear in mind, our system is likely improved a bit since these, due to the influx of the 2017 draft class]. MLB.com had Lugo at #4 and Alcantara #15, with King not ranked in the top 30. John Sickels of Minor League Ball ranked Lugo also at #4, with Alcantara and King outside the top 20. So Lugo’s clearly the best prospect, though you should remember our farm system is relatively weak. The 22-year-old was also largely blocked by Lamb at 3B, the spot he has played at for most of the last two seasons.

Line-up and roster impact

Martinez will provide protection in the line-up, though his position in the order is to be figured out. If I’d to guess, I’d guess at maybe fifth, with Jake Lamb splitting up the two right-handed hitters. The everyday line-up would be:

1. A.J. Pollock, CF
2. David Peralta, RF
3. Paul Goldschmidt, 1B
4. Jake Lamb, 3B
5. J.D. Martinez, LF
6. Chris Owings, 2B
7. Ketel Marte, SS
8. Jeff Mathis/Chris Iannetta, C

Doesn’t appear to have been a need for a 40-man roster move: think Lugo was already on there. It will be interesting to see what the team does with the 25-man roster. Rey Fuentes is probably most likely the loser: he has seen his playing time cut back sharply of late, with only three starts for the entire month of July. This will, however, impact the playing time of Descalso and Herrmann significantly, as they’ve been splitting the starts in left. Although the former has actually been playing reasonably well, after a hellish first month. Since May 7, excluding tonight, Descalso is at .281/.370/.469 over 146 PA. But as a left-handed bat, he’ll still have value and get work.