When Edwin Diaz, the Seattle Mariners' top pitching prospect, was removed from his last start after just two innings, speculation began to swirl. Was he headed to Tacoma? Was he hurt? Was he involved in a trade for Mike Trout? It was all very confusing, but eventually some light was shed on the situation by Jason A. Churchill:
So, Edwin Diaz being slotted into the Jackson bullpen. This suggests solid chance he's in MLB pen within a few months.— Jason A. Churchill (@ProspectInsider) May 9, 2016
While the move was a bit of a surprise, it was understandable. Diaz already flashes big league stuff–his fastball will sit 90-94 mph and occasionally kiss the upper-90s while his slider is a nasty bender that he's comfortable throwing pretty much anywhere–and the main thing holding him back from surging through the system was the lack of a third reliable pitch (Diaz throws a woefully average changeup). The plan made sense, really: get him big league experience, let him develop his changeup on a daily basis with the big league club, and then convert him back to a starter down the road. Simple enough, right?
Dipoto confirms that Edwin Diaz has been converted to a reliever— Ryan Divish (@RyanDivish) May 11, 2016
Yep, everything looks good here. This is definitely a short-term switch and not a permane–:
@C_Muell -- permanent— Ryan Divish (@RyanDivish) May 11, 2016
It's a little weird to see the top pitching prospect suddenly get converted to a relief pitcher, but this speaks more to the ineptitude of the Mariners' farm system than it does to Dipoto's decision making. Despite the pretty stats in Jackson this year, Diaz was flawed. His changeup would need to improve significantly before you'd feel even the slightest bit comfortable giving him multiple trips through a MLB lineup. The fastball and slider are amazing, but there's a reason you don't see any two-pitch starters in the big leagues.
As a late-inning power arm, Diaz will be able to run free with his two-pitch combination. Meanwhile, his already impressive stuff should play up some. Don't get me wrong, I am bummed to see a move where we get less Diaz (innings-wise) and essentially giving up on or delaying a 22-year-old's development on a pitch feels premature, but there is very legitimate potential there for him to be a crazy exciting reliever, and there is a very legitimate chance he could be that crazy exciting reliever in the Mariners' bullpen by the end of the summer.
There are reasons to like this move and there are reasons to hate this move, that's how it goes in baseball and business. But at the end of the day, the Mariners just added a powerful, fast-track bullpen arm to the system and there's really nothing preventing them from one day converting him back to a starter if the changeup (or knuckleball or forkball or that pitch from Rookie of the Year where he floats it) ever comes around.
As far as what this means for the organization's view of Diaz, I don't really view this as them giving up on Edwin Diaz: Starting Pitcher, but instead them trying to extract as much potential out of what they have while the competitive window is so clearly open. This, of course, leads us back to Divish's "permanent" comment. In my opinion, permanent is a silly word in baseball. Rick Ankiel was a pitcher. Chris Hatcher was a catcher. Tom Wilhelmsen was the world's tallest bartender. "Permanent" doesn't carry a ton of weight in this game.
On a closing note, Diaz made his first relief appearance last night, entering in the eighth inning with the Generals clinging to a 3-2 lead against the Birmingham Barons. Diaz struck out two while throwing nine of his thirteen pitches for strikes in an easy 1-2-3 inning.
All was well.