What's next for Mariners after Teoscar trade?

This story was excerpted from Daniel Kramer’s Mariners Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

SEATTLE -- The Mariners made their first offseason splash on Wednesday, acquiring two-time Silver Slugger Award winner Teoscar Hernández from the Blue Jays in exchange for reliever Erik Swanson and Minor League pitcher Adam Macko, who was ranked as Seattle’s No. 8 prospect, per MLB Pipeline.

The transaction wasn’t a shocker, given the Mariners’ need for a power hitter and a corner outfielder and that Hernández had been linked to Seattle over the past few weeks. But now that it’s official, the scope of the Mariners’ offseason is now much clearer.

They’ve checked off one big box
A run-producing corner outfielder was arguably Seattle’s biggest need, and the club believes it hit a home run in filling it with Hernández. Since the start of 2020, his 73 homers rank 15th, his .852 OPS is 20th and his 241 hard-hit base hits (anything 95-plus mph) are tied for 13th among all Major Leaguers.

Moreover, acquiring Hernández one week into the offseason gives a front office that always strikes early a chance to move on to its other notable needs.

“It gives you something that you feel good about plugging into a spot in your lineup that we may have had great uncertainty about a day ago or a week ago or a month ago,” Mariners GM Justin Hollander said. “Certainty is really valuable. Whether you're in the trade market or the free-agent market, there are no guarantees, and so when you have a deal that you're comfortable with and you can do it and it answers a big need, we are generally of the mind to do it.”

How Haniger might still fit
Hollander reiterated that the Mariners would like to bring back Mitch Haniger, but now that they’ve landed Hernández (who is projected to earn $10.65 million), it’s become clearer why Seattle chose not to extend its longtime leader a $19.25 million qualifying offer. A lower salary for Haniger, perhaps even for multiple years, isn’t off the table, but the need to fill his position has diminished significantly.

“There’s still more work to do, we think, and things we'd like to do -- and that includes Mitch Haniger, of course,” Hollander said. “I talked to Adam Karon, his agent, [on Wednesday]. I've been in contact with him throughout, as has [president of baseball operations Jerry Dipoto]. We met with him at the GM Meetings. Certainly the door is still open for Mitch to be back.”

If the Mariners were to bring Haniger back, Hernández -- who was worth minus-3 defensive runs saved in right field -- could move to left, where there’s less clarity on production between Jarred Kelenic and Jesse Winker.

They still must address the middle infield
None among the superstar shortstop class has signed yet, but acquiring Hernández, who is a free agent after 2023, might illustrate the calculus behind the Mariners’ offseason budget. Dipoto and Hollander were willing to go all-in on one player for one year at a more modest rate, rather than splurge for, say, right fielder and AL MVP Award winner Aaron Judge, who sources indicate has never been a realistic target for Seattle.

That’s not to suggest that the Mariners won’t pursue Trea Turner, Carlos Correa, Xander Bogaerts or Dansby Swanson -- all shortstops who’d need to move to second base, if the Mariners have their preference of keeping J.P. Crawford at short -- but they would each also come with a massive payday. The largest free-agent contract under Dipoto is the $115 million deal for Robbie Ray last offseason, and it’s likely that at least Turner, Correa or Bogaerts could net double that.

So, where does that leave second base? The top free agents by Wins Above Replacement are Adam Frazier -- who the Mariners are attempting to replace after a mostly disappointing season -- and Jean Segura, who played in Seattle from 2017-18 and did not coalesce with his teammates. As this front office has shown once again with Hernández, it upgrades most frequently via trades.

They’ll need to replace Erik Swanson
Though the early returns make it seem like the Mariners did well with this trade, filling Swanson’s high-leverage innings will be vital. Swanson registered a 1.7 WAR per FanGraphs, tied for 10th-most among relievers, and his 34.5% strikeout rate was 12th best.

Relievers, however, are perhaps the most replaceable players given the cyclical nature of bullpen success. It’s possible that the Mariners will fill Swanson’s role internally with a prospect such as Bryce Miller (No. 5), or perhaps someone will wow them in Spring Training -- much like Swanson did last year.

“It's a priority,” Hollander said, “and I don't know whether that will be through an external acquisition, whether [Swanson’s] role will be absorbed by the growth and maturation of other guys that we have existing, whether it comes as a trade or free agent or the collective combined development of three pitchers. I can’t answer that today.”