The rotation problem we should be talking about

Anyone paying attention knows the Mariners have had their fare share of underwhelming performances this year. Robinson Cano has an 84 wRC+. Kyle Seager hasn't hit his stride yet and Dustin Ackley was promoted to starting center fielder despite a putrid start at the plate. Mike Zunino still can't hit fastballs. The bullpen has been a shadow of its 2014 self. There's a lot going wrong right now.

For all of Seattle's problems though, the starting rotation has actually been pretty good. Felix Hernandez had a rough outing against Boston but has otherwise looked like his typical Cy Young caliber self. Roenis Elias has done a decent enough impression of his form from 2014 and lazy articles would be lauding the injection of life J.A. Happ's veteran presence brought this team if the Mariners weren't playing so badly. James Paxton scares me by doing things like walking six hitters and then experimenting with a fastball-only approach, but he's throwing ninety-seven and nobody's really squaring him up. Were it just those four, the rotation would be Seattle's biggest strength on the season.

Of course, it hasn't just been those four. Hisashi Iwakuma had three rough starts before landing on the disabled list but the real problem has been Taijuan Walker. After a sterling spring earned the twenty-two year old right-hander a spot in the rotation, Walker has been a disaster since the calendar flipped to April. After giving up seven hits and four walks in 3.2 innings yesterday, Walker has a 7.47 ERA and a 4.99 FIP and the third worst deserved run average in baseball. His curve and cutter are not major league quality pitches right now and between that and bad command, it's easy to see why he's taking his lumps.

This isn't really about Walker though. The Mariners need to coax an effective breaking ball out of him if he's going to be effective, there's no doubt about that, but the club isn't in a position where they can prioritize his development. In most organizations, Walker would be honing his secondary offerings in the minor leagues, where development trumps winning and where he could work on pitches that badly need improvement without worrying about whether a hung curve will cost his team a meaningful ballgame. But Seattle's rotation depth is so thin that even a struggling and wildly inconsistent Walker is a better option than what they have in Tacoma. That in and of itself is a problem.

But what if there's an injury? What if Happ or Paxton or, bless ourselves, Felix went down for an extended period of time? Not only would the Mariners have to roll the dice with Walker each time through the rotation, but they'd have to dip into their inexperienced farm system just to fill out the starting five. It's not Anthony Vasquez-bad down there, but a quick review of the internal rotation candidates suggests that the Mariners are in poor shape if they need more than a spot start. None of the starters in Jackson are qualified for big league work at the moment, leaving Tacoma's low-ceiling rotation as the only realistic options to replace an injured starter.

Here's a quick run down of Tacoma's starters:

Mike Montgomery
The return piece in the trade for Erasmo Ramirez, Montgomery is the odds on favorite to join the rotation if the need arises. Conveniently, he's already on the 40-man roster, and we won't have to worry about significant platoon split problems, as the southpaw has actually pitched a bit better against righties than lefties over the course of his career. That's not quite as encouraging as it sounds: his curve is well below average and he doesn't have an out pitch for same handed hitters. He also has a history of walking people, partially attributable to a slow-then-quick delivery that has led to problems with his release point. He throws hard, and in a best case scenario, he'll have some success by minimizing hard contact in short, inefficient outings.

Justin Germano
The only pitcher with big league experience in the Rainiers rotation, Germano works by spotting his mid-80's fastball and keeping hitters off balance with a decent change up and a surprisingly effective looping curve ball. He's done well with that pitch mix this season, posting a 1.46 ERA in thirty-seven innings split between the rotation and the bullpen. The problem with Germano is that while he's had a lot of time in the majors, he spent most of it getting his ears pinned back. His career pitcher slash is 5.40/4.71/4.56 and most of that came back when he threw harder than eighty-five.

Sam Gaviglio
Gaviglio's recent struggles -- he's allowed at least four runs in four of his last six starts -- likely preclude him from consideration at this point, although he might be the safest option when everything's clicking. He pounds the zone with an 89-91 sinker, mixing in a decent slider and fringy change up when he wants to chase whiffs. His BB/9 is over 4 right now, which bears monitoring because he's never really had a problem throwing strikes before. Remember David Pauley as a starter back in 2010? If it works, he could be like that, down to the same build and sinker-heavy approach.

Stephen Landazuri
The youngest starter on the Rainiers, Landazuri has very quietly crept from 22nd round flier to legitimate prospect. He's touched ninety-four with his fastball, and he also throws a slider, sinker, and change up. He could be a back end starter, but his developing command and lack of experience facing advanced hitters -- he has just one start above Double-A -- would probably be exploited if he was called up right now.

Forrest Snow
Seattle native, University of Washington alum, and Tacoma's first-pitch-catcher Forrest Snow is probably too loose in the zone to start in the majors, although he's pitched well this year and might have the best strikeout stuff of the crop. His go-to pitch is a sinking fastball that touches the mid-90's, and his change and curve are good enough to keep opponents from just sitting on the fastball.

External Options
Realistically, any significant injury will send the front office scrambling for a suitable long term replacement from outside of the organization. I don't want to spend too much time blindly speculating names the M's might pursue in such a situation, but a quick glance at some of the clubs already out of the playoff race reveals a few plausible names. The Brewers would be interested in shopping free-agent-to-be Kyle Lohse at the right price, and the M's would probably get more out of Kyle Kendrick than the Rockies have, without needing to pay much for the opportunity. Each adequately represents the kind of low-cost option that could be acquired quickly and both would be a significant upgrade over the Mariners internal options.

Last season, the Mariners used ten different starting pitchers. In 2013, they used eleven. In 2009, the club had twelve different starters and the M's haven't used fewer than seven over the course of a full season since 2003. Teams generally need at least seven or eight to get through the year -- the Dodgers have already used nine -- and there's no reason to expect the 2015 Mariners to be any different. Most clubs lack enticing options beyond their starting five, although Seattle has particularly inexperienced and unexciting options in their minor league system. The M's probably make a bullpen game of it if they need a spot start, but if they're forced to call upon any of the names profiled above, they'll probably enter the game as underdogs. A significant injury or two to the rotation would be devastating and could cripple the season, even if everything else improves.