Heading into a three-game set in San Diego, and then heading home for three against the hapless Marlins, the D’backs have to take advantage of this relatively soft stretch of games to build a cushion in the standings. Because immediately following, the D’backs have nine games against the Reds, Nationals and Braves, a really tough stretch.

But this series in San Diego this weekend is a lot tougher than it may look. First, the Padres are above .500, 22-18, since May 1 and are 19-14 at home. Plus, Petco has been a house of horrors for the Snakes.

Since Petco opened in 2004, the D’backs are a craptastic 34-51 in San Diego. And much of that is during years where the Padres were really bad. The D’backs could really use a good series there this weekend, perhaps stealing a pair before playing Miami.

This year, the D’backs and Friars have split six games, 3-3, with the D’backs winning 2-of-3 in Phoenix and losing 2-of-3 in Petco.

Game 1 (Friday): Trevor Cahill (3-7, 4.02 ERA) vs. Eric Stults (5-5, 3.53 ERA)

Stults has been consistently solid for the Padres, throwing three-straight quality starts and, what I like to call, super-quality starts, which is seven innings or more of two earned runs or less. In his last outing, he beat the Rockies, tossing seven innings, striking out four and only allowing a single earned run. However, Stults’ last start that did not end with a quality start was an outing against the D’backs on May 24, in which he gave up four earned in 6.1 innings. Against the D’backs all time, he’s 3-3 with a 4.58 ERA in eight games (six starts) and 39.1 innings pitched. Cahill was lit up like a severe lightning storm his last time out, giving up eight earned in only 3.2 innings against the Giants on June 8. It was, by far, his worst outing of the season.

Game 2 (Saturday): Wade Miley (4-5, 4.89) vs. Clayton Richard (1-5, 8.06)

Richard, quite simply, has been horrendous this season. He’s had six outings where he’s given up at least five earned and hasn’t lasted longer than six innings. And he hasn’t been better lately, allowing 10 earned in only 10.1 innings pitched in two starts so far in June. In his lone start against the D’backs on May 4, he was knocked around for five earned in 3.2 innings. Miley, unfortunately, has not been very good either recently. He had back-to-back outings on May 25 and MAy 31 where he gave up seven runs. In two outings in June, he’s given up six earned in 12.2 innings. And he’s been lucky to only have given up that few of runs – he was knocked around for 20 hits in those two outings. In two starts against the Friars, he’s 0-2 with 11 earned in 8.2 innings.

Game 3 (Sunday): TBD vs Jason Marquis (8-2, 3.59)

I write “To Be Determined” for the D’backs because Ian Kennedy is the projected starter on Sunday. However, he’s highly likely to be suspended (should be announced today). Unless he appeals the suspension, possible, the D’backs will have to find a spot starter on Sunday. One option for the D’backs would be Josh Collmenter. Collmenter threw two innings in relief on Wednesday, but has been stretched out to as many as four innings this year in a long relief role. Collmenter could easily slid in for five to six innings on Sunday if that’s the way Kirk Gibson goes. Collmenter is 3-0 with a 2.86 ERA in 34.2 innings of work out of the pen this season. In a previous series preview, I implied that Marquis has been getting lucky so far this season. Now I’ll just say it. There’s no way Marquis stays around a 3.50 ERA for the rest of the year. He’s struck out 50 in 77.2 innings this season, but has also walked 43. And a .240 BABIP against screams regression. Once more hits start to fall, all those walks will start to come around to score.

The bulk of the struggles have largely been limited to those in high-leverage situations, notably JJ Putz and David Hernandez. I was curious to know if these guys were failing to perform like they have in the past or whether this was just a blip on the radar that could be attributed to bad luck and small sample sizes. I wanted to know if this was something that we should be concerned about or whether we could reasonably expect this difficult stretch to pass. After all, they wouldn’t be the first major league pitchers to get off to a slow start, right?

Digging through their performances, pitch-by-pitch, a few things jumped out at me. We’ll take a look at both Putz and Hernandez individually to see just how they’ve been getting exposed.

Arizona Diamondbacks relief pitcher J.J. Putz. IMAGE: Ed Szczepanski – USA Today Sports

It’s no secret that JJ has been excellent for the Dbacks over the last two seasons. He’s built that success largely by doing three things: striking out a lot of batters, issuing very few walks and limiting the number of homeruns he’s allowed. In 2013, he’s still recording a lot of strikeouts (12.8 K/9) but the walks are killing him. He hasn’t posted a walk rate like his current one (4.97 BB/9) since 2009 with the Mets. He’s walked less than two batters per nine innings in each of the last two years, so this current spike is unexpected. Making matters worse, JJ has already surrendered three homeruns through 12.2 innings in 2013 after allowing only four all of last year (54.1 IP) and only four in 2011 (58 IP). If there’s anything we know about pitching, it’s that walks and homeruns are a good recipe for disaster. So far, JJ is way above his norms in both categories.

What’s leading to these issues? Looking at Pitch F/X data, it’s clear that his velocity is down throughout his arsenal. We don’t know if this is simply a matter of him building up early season arm strength or if he simply is losing velocity. At 36-years old, a drop in velocity wouldn’t be surprising. He’s also altered his offerings to hitters, throwing his fastball less often and using his slider more. The slider has been simply average so far and his fastball hasn’t been nearly as effective as usual. But Putz is most notable for his splitter. When he commands the hammer, it’s lights out for hitters. Unfortunately, the splitter is notorious for being one of the most difficult pitches to command in baseball. So far, JJ is having trouble with the pitch and it’s getting crushed. Because of his struggles with throwing consistent strikes, hitters are taking more and chasing less, forcing him to come over the plate and risk getting hit hard. And that’s just what’s happened.

David Hernandez’ struggles have also seemingly come out of nowhere. His recipe for success in the past has been high strikeout rates and not giving up the long ball. Never a control artist, Hernandez is currently right on par with his career walk rate (3.95 BB/9), but his strikeouts are down from last year. More importantly, he’s been burned by the homerun, as opponents have already put four offerings over the fence this year (13.2 IP). He allowed only four dingers in each of the last two years, so his current homerun rate is surprising. Given his propensity to walk hitters, the homeruns are painful. For example, on May 1^st, he entered the 8^th inning protecting a one-run lead. Hernandez walked two hitters before giving up his latest long ball, a three-run heart-breaker that gave the rival Giants a lead they wouldn’t surrender.

Arizona Diamondbacks relief pitcher David Hernandez. IMAGE: Ed Szczepanski – USA Today Sports

So where has David strayed? Why is this happening now? Like Putz, Hernandez has altered his repertoire. He’s throwing his two-seamer 30% more often than last season. This has largely come at the expense of his four-seam fastball, which he’s using 40% less than in 2012. What’s behind this shift is unclear, but it’s not working as his two-seamer is getting hit hard and has been costing him dearly. David’s curveball, his best offering last year, has also been far less effective in 2013. On the bright side, his changeup has improved but without fastball success, the changeup’s usefulness is limited. Like JJ, batters are taking more and chasing less since Hernandez is struggling and hitters know it. They are taking advantage of the situation by forcing David to throw strikes and jumping on hittable pitches.

I wanted to be able to blame the poor results of the back-end of the bullpen on bad luck. Unfortunately, the BABIP of both JJ and David are right in line with their career averages, showing that we can’t just hope for regression to the mean. Instead, there is some puzzling information within just how they are pitching. Will JJ’s velocity pick back up? Can he command the splitter and get it back on track as one of the game’s premier put-away pitches? Will David either get his two-seam fastball under control or start using it less? What about his curve? Can both of these guys find a way to keep the ball in the yard?

The Dbacks season rests in their hands and given the competitive nature of the division, there are sure to be a ton of close games as the season wears on.  Can they rise to the occasion and iron out their issues? We certainly hope so.

Image: Bob DeChiara-USA TODAY Sports

I am especially perplexed at how the D’backs view defense. I’m almost bewildered.Over the past few years, teams have started to focus more on defense and make it a priority in the type of players they sign. It’s almost been a renaissance of sorts in how teams and fans view defense.

And the beginning of this offseason, it looked like the D’backs were right in line with that view by trading for light-hitting but defensive wizards at shortstop in Cliff Pennington and Didi Gregorius. Nevermind the decision to get two shortstops of similar ilk, the point was clear, defense up the middle on the infield was a priority. With above-average defender Aaron Hill at second and vastly improving on defense Paul Goldschmidt at first, the D’backs had the makings of a staunch defensive infield.

Combined with the likes of Gerardo Parra, Adam Eaton and Justin Upton, all well above-average defenders, in the outfield, they had a top-five defensive team in the making.

However, the D’backs went out and signed Cody Ross, who used to be a pretty good defensive corner outfielder but has combined for a -13 defensive runs saved over the past two seasons in the outfield.

Now, news has come out that instead of trading power bat, but no glove Jason Kubel, the D’backs ultimately traded Justin Upton to the Mariners to only have the trade rejected by Upton because his no-trade list included Seattle.

But imagine that the D’backs had traded Upton. That would mean the Ross, a worse defender would be playing right, Kubel would most likely play left field and Eaton and Parra would split time in center.

While Parra and Eaton should be great in center field, Kubel and Ross would not be very good in the corners. So the D’backs would have a great defensive infield and a mediocre defensive outfield.

And the defense in the outfield would be exposed at times with fly ball pitchers Ian Kennedy and Wade Miley on the hill.

So what exactly is the game plan on defense? Does Kevin Towers and company look at defense? They must if they like Pennington and Gregorius. But do they only like it in the infield? Then why keep relatively light-hitting Parra in the lineup when teams were looking for a guy like him on the trade market last year?

See why I’m confused?

And the most frustrating part is that this is one of the less questionable aspects of the D’backs’ 2012-13 offseason.

I guess the best way to end this is with a big #KEEPUPTON!