Apr 27, 2015; Arlington, TX, USA; A view of a Seattle Mariners hat and baseball glove during the game between the Texas Rangers and the Mariners at Globe Life Park in Arlington. The Mariners defeated the Rangers 3-1. Mandatory Credit: Jerome Miron-Imagn Images Jerome Miron-Imagn Images

Mariners Being 'Haunted' By Massive Trade Deadline Mistake

Originally posted on Fastball on SI | By Zach Pressnell | Last updated Sep 6, 2025 3:17 PM ET

The Seattle Mariners made some big moves to add to the offense at the trade deadline, notably adding Josh Naylor and Eugenio Suárez from the Arizona Diamondbacks.

But the Mariners have completely fallen off over the last few weeks. They're slowly losing a grip on the final wild card spot in the American League. At this point, there are a lot of mistakes to point the finger at.

Paul Taylor of Sodo Mojo recently criticized the Mariners for not adding more to the bullpen at the trade deadline. Taylor specifically noted the Mariners' whiff on adding star closer Jhoan Durán from the Minnesota Twins. Durán was traded to the Philadelphia Phillies in a massive deal at the trade deadline.

Mariners didn't add enough to the bullpen at the trade deadline

"As of the end of July, Muñoz was sitting pretty with a 1.32 ERA, 2.29 FIP, 0.93 WHIP and .140 opposing team batting average. Since then however, he's produced a 2.92 ERA, 3.38 FIP, 1.46 WHIP and .245 opposing team batting average," Taylor wrote. "Given all of this, it brings back to mind the only thing the Mariners got wrong at the trade deadline by not acquiring Jhoan Durán.

"To put it simply, he has been exceptional since arriving in Philadelphia. In fact, he's been even better than when he was still with the Minnesota Twins. With the Twins this season, Durán had a 2.01 ERA, 2.53 FIP and 1.18 WHIP with 16 saves in 18 opportunities over 49.1 combined innings. With the Phillies, he has taken his game to another level, recording a 1.54 ERA, 0.74 FIP and 0.86 WHIP with 10 saves in 11 tries during 11.2 combined innings."

Adding Durán would have been a huge boost to the Mariners' roster. He's one of the best closers in the game and sits on a contract with multiple more years of team control.

But it would have been very expensive for Seattle to pull off. It doesn't seem like it would have been a very reasonable move, especially with Andres Muñoz on the roster. He's fallen off a bit, but there's no reason to be too concerned.

However, the Mariners have a lot of other problems to be addressed. Cal Raleigh and Eugenio Suárez have struggled, and the Mariners will need them to pick the production up down the stretch.

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This article first appeared on Fastball on SI and was syndicated with permission.

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