Catcher: Cal Raleigh (4.7 fWAR) is 3rd out of 45
Cal Raleigh had a fantastic season, and I don't think there is any argument against that. Sure, maybe you want a higher batting average. Raleigh "only" hit .232/.306/.456 with a 111 WRC+, but he provided a great mix of power (30 bombs, a club record) and was a menace behind the dish, posting the 3rd highest dWAR mark on fangraphs for a catcher. He also threw out the most runners at 20, 5 more than an average catcher would get. Nicely done, Big Dumper.
First Base: Ty France (0.5 fWAR) 34th out of 53
Uggh. If you've read my stuff for a while, you know that I am a fan of Ty France, and have spoken his praises many a time. Shoot, it even went so far as projecting him to win the batting title in the past. This year was a lot different. He still got hit a ton, but he just didn't produce like the Mariners needed. When you pair that with his worst defensive season, it's not a good look. He was bad at first this year, and hopefully he goes to Driveline this offseason.
Second Base: Jose Caballero (2.2 fWAR) 21st out of 56
Second Base: Josh Rojas (1.1 fWAR) 32nd out of 56
Second Base: Kolten Wong (-1.1 fWAR) 353rd of 362. GROSS
Big ol group here, as the Mariners had three people essentially take up second base this season. First, there was literally one of the worst players in baseball in Kolten Wong. I have to eat my words here, because I said he was going to be good. He still should've been based on history, and there was nothing to portend this happened. 353 out of 362 players though? Ick.
Then, there was Rojas and Cabby. They did an admirable job, if not downright good job at second. Rojas was much better in Seattle than he was in Arizona, and Cabby was a menace on the bases and at messing with pitchers heads. 3.3 combined fWAR from those two? Amazing.
Third Base: Eugenio Suarez (3.2 fWAR) 10th of 58
Geno struck out. A LOT. However, he played great defense at the hot corner, making up for the lack of bat. There were a healthy amount of impressive plays there by him this season, and if we can get some kind of 2022 offense and 2023 defense combo, we could see a great season in 2024... somewhere in the 5-5.5 fWAR range, if not 6.0. As it was, he was still a top-ten third baseman in 2023, a fact that went unrealized by many this year.
Shortstop: JP Crawford (4.9 fWAR) T-4th of 49
Corey Seager. Francisco Lindor. Bobby Witt Jr. Those are the only shortstops that finished ahead of JP this year in fWAR. He tied with Dansby Swanson at 4.9, and that's the SS that everyone wanted the Mariners to go out and get heading into the 2023 season.
Do you know what's even more impressive? JP was the second best offensive shortstop in baseball this year, behind only Corey Seager. That's actually where the entirety of his value comes from, as he turned in a replacement level mark on defense. Maybe there is something to moving him to second if you can get a "real" shortstop, but it's definitely not going to be because his bat isn't good enough for a prime position on the field.