Michael Siani and Jose Fermin
Two more names I really don't understand having on the 40-man roster are Michael Siani and and Jose Fermin.
The best argument for Fermin would be that beyond Masyn Winn and Tommy Edman, the Cardinals' depth at shortstop is razor-thin at the moment. Thomas Saggese is the next guy up, but that's a lot of pressure to put on the guy, and he would profile better defensively at third base or second base.
Fermin did not do anything in 2023 to warrant consideration for the roster in 2024. In 21 games, Fermin slashed .235/.339/.255 with one double and four RBI on the season. There's not much of a ceiling here, and I think the Cardinals would be better off letting Saggese rise to the occasion or bringing in a veteran backup infielder who can handle shortstop.
Siani is an odd one to me as well. The Cardinals claimed him from the Reds during the 2023 season, and Siani went hitless in his five plate appearances with St. Louis. His major appeal is his defensive ability in center field, providing depth for the Cardinals organizationally.
Honestly, though, I think they are fine with what they have. Tommy Edman, Lars Nootbaar, Dylan Carlson, and Richie Palacios can all man center field as needed at the moment, and Victor Scott II is knocking at the door of St. Louis as well. Even if a bunch of injuries happen, I don't really see a world where Siani has a role with the club.
And that's the thing. I could see a world where Naughton or Rodriguez had roles with St. Louis in 2024, so why not keep names like that?
Instead, Siani and Fermin remain on the 40-man roster, but that could change at any moment.