This offseason has been a frustrating one to date so far for Mariners fans. After Ohtani signed with the Dodgers things will start to pick up, hopefully, and we will see some additions to the Mariners roster. One blow the Mariners took was when KBO star Jung-Hoo Lee signed with the Giants for a pretty rich contract. With that signing, however, the Giants have 3 or 4 solid outfielders as well as a top prospect that debuted last year and I think the Mariners could match up really well with them for an outfield bat.
The Mariners should target Austin Slater
Austin Slater might not be the name you want the Mariners to target when talking about an outfield consisting of Michael Conforto, Mike Yastrzemski, and Mitch Haniger, but make no mistake, he has been a very good hitter. Slater is also only $4 million this year and will be a free agent after the year, so the cost to acquire him, as well as his salary, will be fairly minimal.
In 2021 and 2022, Slater combined for 3.7 fWAR and if he would have gotten a similar number of at-bats this year, he was on pace for another 1.5-win season. Like I said, he kind of fell down the depth chart last year with Conforto, Haniger, Joc Pederson, and emerging youngster Luis Matos. In 2023, he slashed .270/.348/.400 with a 110 wRC+ and solid walk and strikeout rates, 9.7% walk rate, and 28% strikeout rate. He has a career 108 wRC+ and .345 on-base-percentage, something Dipoto will most certainly love. His strikeout rate is a little elevated for his career at 27.6% but he makes up for it with his high on base ability and a solid 10.4% walk rate.
Slater makes even more sense for the Mariners when you pair it with Dipoto's recent comments that they will most likely be looking for a right-handed bat to platoon with Dominic Canzone in a corner outfield spot. When you are looking for the right-handed side of a platoon, it is hard to do much better than Slater. In his career, Slater has slashed .285/.374/.463 versus lefties with a 131 wRC+. He has a very solid 22.7% strikeout rate against them as well. This would give you a really solid option to put in the 5-7 hole on days when there is a left-handed pitcher on the mound.
Finally, when it comes to defense, Slater won't be a liability at all. He has graded out as about an average centerfielder and a slightly above-average corner outfielder. It does look like he might have a little bit of a weaker arm, but if he can cover some ground, make the plays needed, not hurt you out there, and be a solid platoon bat, Austin Slater could prove to be one of the best under the radar additions of the offseason.