Seattle has one of the most talented farm systems in the league, meaning Cincinnati could cash in on some top-level talent if they decide to part with Castillo this offseason.
What Seattle would be willing to give up in order to land Castillo is anyone's guess, but let's outline three possible trade packages the Mariners could craft in order to pry La Piedra away from the Reds.
1. Reds land prospect-heavy package for Luis Castillo.
Yes, landing a player like Julio Rodriguez would be a dream scenario for the Cincinnati Reds. But Nick Krall better keep on dreaming.
The M's are unlikely to move Rodriguez, as Seattle has high hopes for the No. 2-rated prospect in all of baseball per MLB Pipeline.
But, the Mariners still have five other prospects listed among the Top 100 in the sport. In order to land Castillo, you'd have to think that Seattle would have to part with at least one.
In this scenario, the Reds would pocket two of the Mariners' top prospects. Right-handed pitcher George Kirby and catcher Harry Ford are both ranked in the Top 100.
Kirby was a first-round pick of the Mariners in 2019. The 6-foot-4 right-hander has a four-pitch mix and great command.
Kirby is not going to put a lot of men on base. Last season at Double-A Arkansas, the 23-year-old posted a 6.4% walk-rate.
Harry Ford was one of the top catching prospects in last year's draft. It's always a risk taking a catcher out of high school in the first-round, but it seems to have worked out well for the Reds.
After being taken in the first-round out of high school in 2015, Tyler Stephenson showcased his talents last season and will be firmly entrenched as Cincinnati's everyday catcher in 2022.
Zach DeLoach is a left-handed hitting outfielder who has a chance to stick in center field. DeLoach is a streaky hitter, but could develop into a solid outfielder.