Breaking Down The Mariners/Rays Trade (Karns A Bust, Miller Worth Targeting & More)

by Eric Stashin (aka The Rotoprofessor)

The Trade:
The Seattle Mariners Acquire: RHP Nate Karns, LHP C.J. Riefenhauser & OF Boog Powell
The Tampa Bay Rays Acquire: INF/OF Brad Miller, 1B Logan Morrison & RHP Danny Farquhar


The Mariners Fallout:
The key to the deal is obviously Karns, who posted some solid numbers over 147.0 IP for the Rays last season:

  • ERA – 3.67
  • WHIP – 1.28
  • Strikeouts – 8.88 K/9
  • Walks – 3.43 BB/9

That said we have to question his ability to maintain the strikeout rate.  He doesn’t generate many swings and misses (9.2% SwStr%) and he also doesn’t get opponents to chase outside the zone (29.5% O-Swing%).  He did own a 10.3 K/9 over 449.1 IP in the minors, which does offer some promise, but the underlying numbers speak volumes.

When coupled with mediocre control (3.8 BB/9 in the minors) and an unimpressive groundball rate (41.9%), the acquisition has the potential to ultimately be a bust.

The team did alleviate a little bit of the “log jam” at shortstop, where Miller had been an option along with Ketel Marte.  If the team brings in another option remains to be seen, though Marte gets a bump in value for the time being.  They also cleared some AB at 1B, which could be given to Mark Trumbo/Jesus Montero, depending on what the rest of the offseason brings.

Riefenhauser has struggled in 24 appearances for the Rays over the past two seasons, averaging just 89.2 mph on his fastball.  It’s hard to imagine much from him.  Powell split time between Double and Triple-A, with 3 HR and 18 SB over 444 AB and looks more like a depth outfielder.


The Rays Fallout:
Cashing in on Karns makes sense, given the concerns we noted above.  It will be interesting to see if the Rays see Miller in a Ben Zobrist like role, as he saw action at 2B, 3B, SS and all three outfield spots last year.  He showed both power (11 HR) and speed (13) in his 438 AB in the Majors last season, and he does offer 20/20 upside.  The problem has been his average, though he made some significant strides last season:

  • Strikeouts – 20.3% (19.7% in the second half)
  • Line Drives – 202%
  • Popups – 8.4%

Coupled with a believable .307 BABIP, which could actually increase given his speed, and there’s reason to believe.  He should be considered a prime late round target, as others have likely become frustrated by the hype.

Morrison isn’t a sexy option, but he could slide into a 1B/DH role.  The Rays are consistently looking for pop for the lineup and he did hit 17 HR last season.  Sure it came with a .225 average, though his 16.3% line drive rate is hardly believable.  He’s going to hold value in deeper formats, at least as a flier/plug-in option.

Farquhar could be the latest reclamation project for the back of the bullpen, as the one-time closer posted a 5.12 ERA last season.  He’s fantasy irrelevant, however.


Sources – Fangrahs, Baseball Reference,

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