Teoscar Hernandez
The big bat that the Mariners acquired last offseason was a big disappointment for the Mariners. He was slightly above average with a 105 wRC+, leading the Mariners to decline to offer him the qualifying offer. He then signed a deal with the Dodgers and, surprise surprise, he is raking! In 25 games he is slashing .258/.337/.462 with five home runs. His hideous strikeout rate continues, at 34%, but he has put up a 122 OPS+. This is about what Mariners fans expected to happen.
Jose Caballero
The spark plug of the 2023 team, Caballero found himself without a roster spot heading into the 2024 season. It seemed like a great trade for the Mariners when they sent him to Tampa Bay for Luke Raley, and it still very well could be. However, Caballero has been really solid filling in at shortstop for the Rays. In 22 games, Caballero is hitting .269/.301/.436 with two home runs and eight stolen bases. Caballero has been a very solid player, someone the Mariners would probably like to have, but they just don't have a spot for him. Good thing Luke Rayley has been getting a ton of time for the Mariners... (that was sarcasm as he has just 36 plate appearances).
Mike Ford
A great story of the 2023 team, Mike Ford carried this offense at times. Ford gave them some stability at a DH position that has been a huge void. The Mariners wanted to upgrade that even further, with the signing of Mitch Garver. Ford signed a minor league deal with the Reds and has been destroying Triple-A. He is slashing .292/.366/.583 with six home runs in 19 games. he has an impressive 11% walk rate and a 19.5% strikeout rate. The Reds have a very talented infield, and with their DH position struggling so far, I wouldn't be surprised to see Ford in the red and white very soon.
Chris Flexen
Flexen signed a one-year deal with the White Sox, a team that was reallly lacking starting pitching, especailly after trading Dylan Cease. Flexen has not been good this year. He has made five appearances, with three starts, throwing 19.2 innings with a whopping 6.41 ERA. The Mariners found lightning in a bottle when they brought Flexen over from the KBO, but he has yet to replicate that success.
Justin Topa
Topa was one of the best and most surprising relievers in the Mariners 2023 bullpen. Topa was included in the deal that netted the Mariners Jorge Polanco. He was a key departure for this team that has built its success on a very good bullpen. Unfortunately, Topa has yet to pitch with the Twins. He was placed on the 15-day injured list before the season started, with left patellar tendinitis. Hopefully we get to see Topa soon, he was a very solid reliever and a great story.