New general manager Jerry Dipoto hasn't wasted any time in making his presence felt by the M's faithful, completing the first trade of the winter a mere 37 days after being hired. The details, as you have been made abundantly aware by now: INF/OF Brad Miller, 1B/OF Logan Morrison, and RHP Danny Farquhar were shipped to Tampa Bay in exchange for RHP Nathan Karns, LHP CJ Riefenhauser, and OF Boog Powell.
The real meat of this deal lies in the swapping of the first players listed. Tampa was in desperate need of a shortstop, and thanks in no small part to Ketel Marte being so good, Miller became expendable. Meanwhile, the Mariners just finished giving Vidal Nuno 10 starts in August and September, so I think it's fair to say that they needed some additional pitching depth behind Felix, Iwakuma, and Walker. Enter Nathan Karns, who posted 1.5 wins above replacement, and had an xFIP of 3.90 in 27 games (26 starts) for the Rays in 2015. Those numbers would have placed him fourth among M's starters last year, so he seems like a logical candidate to slide into the back end of a rotation, right?
I have no idea, because smarter people than me, who have better things to say, have already addressed the important parts of this deal. I'm just a guy who likes to watch minor league baseball. So if you haven't yet had time to do some searching on your own to find out about the other two guys the M's got in this trade, let me introduce them to you.
Riefenhauser was a 20th round pick of the Rays way back in 2010. He's a guy who steadily climbed through their system, culminating in an appearance in the 2013 futures game, which was probably the peak of his prospect value. He's a 6'0 190 lb lefty who sits 89-92 with a fastball that has a tiny bit of break, a slider and a changeup. His slider has been noted as lacking a ton of horizontal movement, and was even classified as a curve by Kiley McDaniel in last season's evaluating the prospects series. Here's a good example of both the fastball and slider, from 2013:
Riefenhauser can throw strikes, but big league hitters aren't going to foul off those fastballs as often as AA guys will. While he spent the first few years of his career putting up eye popping numbers in the minors, some of the shine has worn off because the results have not been there when he's gotten a chance in the majors. After getting torched with the Rays in a couple of call ups earlier in the season, he fared much better after rosters expanded in September. In his final 8.1 innings, he gave up only 7 hits and 2 ER, with 3 walks and 5 K's. Riefenhauser will be another piece trying to fight through the pile in Arizona, battling guys like Tyler Olsen, David Rollins, and Paul Fry for a lefty spot in the 2016 M's pen. He's still got a couple of option years left, so my guess is that he starts the season in Tacoma, but sees Safeco at some point during the summer.
The more interesting piece of this trade to me, at least long term, is Boog Powell. The CF prospect was another 20th round pick, but of the Oakland A's in 2012, and was traded to Tampa Bay back in January in the Ben Zobrist deal. He's a player who brings a skill set that the new front office really values: speed, on base ability, and defense. Between AA Montgomery and AAA Durham last season, he hit .295 with a .385 OBP and stole 18 bases. While the Mariners might want to work with him a bit on when and how to run (he also was caught stealing 14 times in 2015), the ability to get on base is real, and he's also a much better defender than someone like James Jones. Powell profiles as an ideal top of the order type player, never posting a walk rate below 10.6%, or a strikeout rate above 16.7%, and he's only 22 years old. Here's a thing that he does:
Boog has only got 56 games of AAA experience so far in his career, and has almost no power to speak of, so he is by no means a lock to break camp with the Mariners. But he's a kid who has put up consistent numbers across every level of competition he's faced and seems to know what kind of player he is. Like all baseball trades, only time will write exactly how this one plays out. But turning one Brad Miller into a reliable 4th starter, and also a possible starting center fielder? I can't complain about that.